Monitoring of Elemental Composition of Honey from Selected ...

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Monitoring of Elemental Composition of Honey from

Selected Regions of Ghana Using Instrumental Neutron

Activation Analysis and Atomic Absorption Spectroscopy

A thesis submitted to the

DEPARTMENT OF NUCLEAR SCIENCES AND APPLICATIONS,

SCHOOL OF NUCLEAR AND ALLIED SCIENCES,

COLLEGE OF BASIC AND APPLIED SCIENCES,

UNIVERSITY OF GHANA

By

Randy Boateng

10277981

Bsc. Chemistry (Ghana), 2012

IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF

MASTER OF PHILOSOPHY

IN

NUCLEAR AND RADIOCHEMISTRY

JULY, 2015

University of Ghana http://ugspace.ug.edu.gh

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TABLE OF CONTENT

TABLE OF CONTENT ...................................................................................................... ii

DECLARATION ............................................................................................................... vi

DEDICATION .................................................................................................................. vii

ACKNOWLEDGMENT.................................................................................................. viii

LIST OF TABLE ............................................................................................................... ix

LIST OF FIGURES ........................................................................................................... xi

LIST OF ABBREVIATIONS .......................................................................................... xiii

ABSTRACT ...................................................................................................................... xv

CHAPTER ONE ............................................................................................................... 1

INTRODUCTION .............................................................................................................. 1

1.1 Background ............................................................................................................. 1

1.2 Statement of the Problem ......................................................................................... 4

1.3 Objectives of the Study ............................................................................................ 5

1.3.1 General Objective .............................................................................................. 5

1.3.2 Specific Objectives ............................................................................................ 5

1.4 Relevance and Justification ..................................................................................... 6

1.5 Scope and Delimitation .......................................................................................... 8

CHAPTER TWO ............................................................................................................ 10

LITERATURE REVIEW ................................................................................................. 10

2.1 Definition of Honey .............................................................................................. 10

2.2 Composition of Honey .......................................................................................... 10

2.3 Production of Honey by Bees................................................................................. 13

2.4 Classification of Honey .......................................................................................... 14

2.5 Nutritional and Health Benefits of Honey.............................................................. 15

2.5.1 Energy Food .................................................................................................... 15

2.5.2 Sweetener......................................................................................................... 15

2.5.4 Skin Care ......................................................................................................... 16

2.5.5 Cough Suppressant .......................................................................................... 16


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2.5.6 Source of Antioxidants .................................................................................... 16

2.5.7 Children Nutrition............................................................................................ 17

2.6 The Honey Industry in Ghana ................................................................................ 18

2.6.1 Traditional Test for Determining the “Purity” of Honey ................................ 18

2.6.2 Production Levels and Trends ......................................................................... 19

2.7 Possible Contaminants and Toxic Compounds in Honey ...................................... 21

2.7.1 Heavy Metals .................................................................................................. 21

2.7.2 Classification of Heavy Metals Based on Their Importance .......................... 22

2.7.3 Occurrence and Toxicity of Selected Heavy Metals ...................................... 23

2.7.3.1 Arsenic (As) .................................................................................................. 23

2.7.3.2 Lead (Pb) ...................................................................................................... 24

2.7.3.3 Cadmium (Cd) .............................................................................................. 25

2.7.3.4 Chromium (Cr) ............................................................................................. 26

2.7.3.5 Mercury (Hg) ................................................................................................ 26

2.7.3.6 Copper (Cu) .................................................................................................. 27

2.7.3.7 Zinc (Zn) ...................................................................................................... 28

2.7.3.8 Manganese (Mn) ........................................................................................... 28

2.7.3.9 Vanadium (V) ............................................................................................... 29

2.7.3.10 Cobalt (Co) ................................................................................................. 30

2.8 Studies on the Composition of Honey.................................................................... 31

2.9 Neutron Activation Analysis Technique ................................................................ 35

2.10 Atomic Absorption Spectroscopy Analysis Technique ....................................... 38

CHAPTER THREE ........................................................................................................ 40

MATERIALS AND METHODS ...................................................................................... 40

3.1 Honey Sample Collection Sites .............................................................................. 40

3.2 Social Experiment (Questionnaire Administration) ............................................... 43

3.3 Physicochemical Analysis ...................................................................................... 43

3.3.1 Apparatus ......................................................................................................... 43

3.3.2 Instruments ...................................................................................................... 44

3.3.3 Experimental Procedure ................................................................................. 44

3.3.3.1 Preparation of 10% (w/v) Honey Solution .................................................. 44


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3.3.3.2 Determination of pH ..................................................................................... 44

3.3.3.3 Determination of Electrical Conductivity ..................................................... 44

3.3.3.4 Determination of Relative Density (Specific Gravity) ................................. 45

3.4 Determination of Heavy/Trace Metals ................................................................... 46

3.4.1 Instrumental Neutron Activation Analysis ...................................................... 46

3.4.2 Instrumentation ................................................................................................ 46

3.4.3 Standard Reference Materials ......................................................................... 47

3.4.4 Apparatus ......................................................................................................... 47

3.4.5 Procedure for Sample Preparation ................................................................... 47

3.4.6 Irradiation of samples and standards ............................................................... 48

3.4.7 Measurement of γ-radiation Intensity (Counting) ........................................... 48

3.4.8 γ-ray Spectrum Acquisition and Quantification .............................................. 49

3.4.9 Calculation of Concentration .......................................................................... 49

3.4.10 Validation of the INAA Technique ............................................................... 50

3.5 Determination of Pb, Cr, Co and Fe Using Atomic Absorption Spectroscopy ..... 50

3.5.1 Instrumentation ............................................................................................... 50

3.5.2 Chemicals and Standards ................................................................................. 51

3.5.3 Procedure for Digestion of Samples with the Hot Plate .................................. 51

3.5.4 Chemical Reactions that Occurred During Digestion ..................................... 52

3.5.5 Calibration of Atomic Absorption Spectrophotometer ................................... 53

3.5.6 Determination of Concentration of Honey Sample ......................................... 54

3.5.7 Calculation of Concentration ........................................................................... 55

3.6 DATA ANALYSIS ............................................................................................... 56

CHAPTER FOUR ........................................................................................................... 58

4.0 RESULTS AND DISCUSSION ................................................................................ 58

4.1 Response From Administered Questionnaires ....................................................... 58

4.2 Physicochemical Studies ........................................................................................ 60

4.2.1 pH of Honey ................................................................................................... 60

4.2.2 The Electrical Conductivity of Honey ............................................................. 63

4.2.3 The Specific Gravity of Honey ....................................................................... 64

4.3 Results of Elemental Concentration Determination ............................................ 64


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4.3.1 Validation of INAA Results ........................................................................... 64

4.3.2 Elemental Content of Honey from the Three Regions of Ghana .................. 66

4.3.3 Elemental Concentrations of Honey from Brong Ahafo Region ................... 71

4.3.4 Elemental Concentrations of Honey from Ashanti Region ................................ 77

4.3.5 Elemental Concentrations of Honey from Greater Accra Region...................... 85

4.4 Comparison of Elemental Compositions of Ghanaian Honey at the Various

Sampling Site ................................................................................................................ 91

4.5 Variations of Metal Content of Ghanaian Honey as it goes Through the Various

Processes ....................................................................................................................... 92

4.6 Comparison of Elemental Composition of Honey from the Three Regions Studied

With Other Locations .................................................................................................... 98

CHAPTER FIVE .......................................................................................................... 101

5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................ 101

5.1 CONCLUSIONS ................................................................................................. 101

5.2 RECOMMENDATIONS ................................................................................... 102

LIST OF REFERENCES ............................................................................................. 104

APPENDIX ..................................................................................................................... 116

APPENDIX A ............................................................................................................. 116

APPENDIX B ............................................................................................................. 118

APPENDIX C ............................................................................................................. 123

APPENDIX D1 ........................................................................................................... 126

APPENDIX D2 ........................................................................................................... 129


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DECLARATION

I, Randy Boateng, do declare hereby that the work presented in this dissertation was carried

out by me at the Department of Nuclear Sciences and Applications, School of Nuclear and

Allied Sciences, College of Basic and Applied Sciences, University of Ghana, Legon,

under the supervision of Dr. Charles Kofi Klutse and Dr. Dennis Kpakpo Adotey.

Signed........................................

RANDY BOATENG

(STUDENT)

DATE.......................................

Signed......................................... Signed............................................

DR. CHARLES K. KLUTSE DR. DENNIS K. ADOTEY

(SUPERVISOR) (SUPERVISOR)

DATE......................................... DATE............................................


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DEDICATION

This work is dedicated to my Father, Mr. Twene Adane and my Mother, Mrs. Elizabeth

Durowaa Boateng whose prayers, encouragement, assistance and hard work have brought

me this far.


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ACKNOWLEDGMENT

My sincere gratitude goes to the Almighty God Jehovah for taking me through this

institution and for his guidance in making this project a success.

I am also grateful for the good will and generosity of my supervisors Dr. Charles Kofi

Klutse and Dr. Dennis Kpakpo Adotey for their excellent work done in supervising me

throughout this work, and the strong sense of fairness and openness they exhibited as

lecturers. It is through them that the nucleus of this work was drawn.

I am very grateful to the West African Agricultural Productivity Programme (WAAPP) for

financially sponsoring my studies.

I also wish to extend a depth of gratitude to Mr. Twene Adane, Mrs. Elizabeth Boateng,

Twene Adu-Asare, Cindy Nketia and Barbara Efua Buckman, who supported and prayed

for me to come this far.

I will also like to thank all the staff at National Nuclear Research Institute (NNRI),

especially Mr. N. S. Opata, Mr. Isaac Baidoo and Mr. Ekow Quagraine who assisted me in

analysing my samples at the neutron activation analysis (NAA) laboratory of GAEC.

Thanks also to Mr. Nash Bentil, Mr. Michael Ackah and Mr. Sheriff Enti-Brown at the

atomic absorption spectrometry laboratory, GAEC, for their support and perceptive advice.

Finally, I would like to acknowledge the debt I owe my course mates for their immense

contribution towards this work especially David Larbi, John Andrew Gyenfie and Suraj

Issaka. Their commitment, ideas and enthusiasm motivated me a lot in this work.


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LIST OF TABLES

Table 2.1: Honey Composition (data in g/100 g) ............................................................ 12

Table 2.2: Estimated Production Levels of Honey in Ghana ........................................... 19

Table 2.4: The Toxicity of Certain Heavy/Trace Metals to Humans ............................... 31

Table 3.1: The sampling sites of the honey samples in the various regions ................... 41

Table 3.2: Irradiation and Counting Schemes ................................................................. 48

Table 3.3: Standards Prepared for the Calibration of the AAS ....................................... 54

Table 3.4: Flame AAS Instrument parameter for Pb, Fe, Cr, Co Analysis ..................... 55

Table 3.6: Detection Limit of Elements Determined by AAS ........................................ 56

Table 4.1: The pH, Electrical Conductivity, and Specific Gravity .................................. 62

Table 4.2: Comparison of pH of Ghanaian honey with that from other parts of the world

........................................................................................................................................... 63

Table 4.3: Comparison of Measured and Prepared Standards - Results of 10 mg/L and 20

mg/L Single Standard Elements used for the Validation .................................................. 65

Table 4.4: Mean Elemental Composition of Honey from Brong Ahafo .......................... 68

Table 4.5: Mean Elemental Composition of Honey from Ashanti region ....................... 69

Table 4.6: Mean Elemental Composition of Honey from Greater Accra ........................ 70

Table 4.7: Accepted levels of some parameters in honey ................................................ 94

Table 4.8: Comparison of Elemental Composition of Honey from the three Regions

Studied with other Locations .......................................................................................... 100

Table B1: Results of the elemental composition of honey from the Brong Ahafo region

......................................................................................................................................... 118

Table B2: Results of the elemental composition of honey from the Ashanti region ..... 120


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Table B3: Results of the elemental composition in honey from the Greater Accra region

......................................................................................................................................... 122

Table C1: P- Values calculated for the variations of the elements in the samples (Brong

Ahafo Region) ................................................................................................................. 123

Table C2: P- Values calculated for the variations of the elements in the samples (Ashanti

Region) ............................................................................................................................ 124

Table C3: P- Values calculated for the variations of the elements in the samples (Greater

Accra Region) ................................................................................................................. 125


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LIST OF FIGURES

Figure 2.1: Gender distribution of beekeepers in Ghana (Source: SNV Ghana, 2010) ... 21

Figure 2.3: A typical Gamma ray Spectra (source; Hamidatou et al., 2013) ................... 38

Figure 3.1: Sample collection chart ................................................................................ 40

Figure 3.2: Map of Ghana showing the sampling sites ................................................... 42

Figure 4.1: Response to questions about the location apiaries ....................................... 58

Figure 4.2: Response to questions about addition of additives ....................................... 59

Figure 4.3: Response to questions about packaging materials used for storing honey ... 60

Figure 4.4: Variation of Pb concentrations in honey from selected sampling sites ......... 67

Figure 4.5: Concentration of Co in all the samples analysed.......................................... 72

Figure 4.6: Concentration of Pb in all the samples analysed .......................................... 73

Figure 4.7: Concentration of Cr in all the samples ......................................................... 75

Figure 4.8: Concentration of Fe in all the samples analysed .......................................... 76

Figure 4.9: Concentration of Mg in all the samples analysed ......................................... 79

Figure 4.10: Concentration of V in all the samples analysed ......................................... 80

Figure 4.11: Concentration of Cu in all the samples analysed........................................ 81

Figure 4.12: Concentration of Al in all the samples analysed ........................................ 82

Figure 4.13: Concentration of Ca in all the samples analysed ........................................ 87

Figure 4.14: Concentration of Mn in all the samples analysed ....................................... 88

Figure 4.15: Concentration of K in all the samples analysed ......................................... 89

Figure 4.16: Concentration of Na in all the samples analysed........................................ 90

Figure A1: Linear Regression Line for Calibration of AAS for Analysis of Co ........... 116

Figure A2: Linear Regression Line for Calibration of AAS for Analysis of Pb ........... 116


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Figure A3: Linear Regression Line for Calibration of AAS for Analysis of Cr ............ 117

Figure A4: Linear Regression Line for Calibration of AAS for Analysis of Fe ............ 117


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LIST OF ABBREVIATIONS

A/R Ashanti Region

AAS Atomic Absorption Spectroscopy

AES Atomic Emission Spectroscopy

ANOVA Analysis of Variance

AP After Processing

ATSDR Agency for Toxic Substances and Disease Registry

B/A Brong Ahafo Region

BP Before Processing

EPA Environmental Protection Agency

EU European Union

FAO Food and Agricultural Organisation

FDA Food and Drugs Authority

G/R Greater Accra Region

GSA Ghana Standard Authority

GHARR-1 Ghana Research Reactor -1

HPGe High Purity Germanium

IARC International Agency for Research on Cancer

INAA Instrumental Neutron Activation Analysis

LSD Least Significant Difference

MoFA Ministry of Food and Agriculture

NHB National Honey Board

NIST National Institute of Science and Technology (USA)

RT Retailers


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SNV Stichting Nederlandse Vrijwilligers (Netherlands

Development Organisation, Ghana)

TRXRFS Total Reflection X-ray Florescence spectrometer

US NRC United States Nuclear Regulatory Commission

USA United States of America

WHO World Health Organisation


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ABSTRACT

Honey is a sweet, thick and viscid fluid collected from beehives and usually found in cells

of the honey comb. It is produced from nectar collected from various flowers by honeybees

and processed. Among the important uses, pure and undiluted honey serves as natural

sweetener and contains a broad variety of vitamins for human consumption. Due to its

global demand, monitoring of the quality of honey is of great significance. In this study,

honey samples were collected systematically from farmers and retailers in the Brong

Ahafo, Ashanti and Greater Accra regions of Ghana. The sampling was done along the

farmer-to-trader channels, to assess the quality of honey produced from various regions

and to trace the sources of elemental contamination. Physicochemical studies; pH,

electrical conductivity and specific gravity were done. The levels of selected toxic heavy

metals (Hg, Pb, Cd, V, Cr, As) and essential metals (K, Na, Ca, Mg, Mn, Cu, Fe, Co) in

the honey samples were analysed using instrumental neutron activation analysis (INAA).

Flame atomic absorption spectrophotometry (FAAS) was also employed to determine

elements such as Pb, Co, Cr and Fe. All the honey samples were found to be acidic, with

pH ranging from 3.60 to 6.10. The acidity of honey is significant as it inhibits the growth

of microorganisms. The values agrees favourably with the permitted pH limits of 3.40 to

3.60 for good quality honey, set by the National Honey Board of United States. The

electrical conductivities measured ranged from 11.9 µS/cm to 44.4 µS/cm. The values were

within the acceptable limits set by Ghana Standards Authority and other organizations

(<800 µS/cm). The specific gravity of the honey samples analysed ranged from 1.297 to

2.031. These values were higher than the values (1.2081 to 1.2270) reported in Libyan


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Honey. However, these values were closer to the average specific gravity (1.425) value

reported in other studies. These variations in the specific gravity may be related to the

differences in the chemical composition of the honey. The results indicated that the metal

contents of the honey were in the order: K > Ca > Na > Mn > Al > Mg > Cu > V > Fe > Pb

> Co > Cr, in the selected sampling sites evaluated in the three regions. The values ranged

from 0.009 – 0.094 mg/kg for Co; 0.010 – 0.423 mg/kg for Pb; 0.010 – 0.423 mg/kg for

Cr; 1.548 – 11.052 mg/kg for Fe; 0.490 – 35.021 mg/kg for V; 4.524 – 288.298 mg/kg for

Cu; 75.697 - 681.236 mg/kg for Mg; 60.159 – 1186.369 mg/kg for Al; 145.668 – 3501.004

mg/kg for Mn; 900.214 – 8277.351 mg/kg for Na; 2.393 – 283.690 g/kg for Ca and 112.933

– 1770.770 g/kg for K. With the exception of Cu, the concentrations of the metals were

below the permitted limits sets by Ghana Standards Authority, Codex Alimentarius and the

Polish Standards. The metal contents of the honey in the various regions considered were

similar. There were significant differences in concentrations in most of the samples as

monitored from one sampling site to the other. Significant differences in concentrations

was also observed as the honey goes through treatment processes. This affirms that the

various processes honey goes through prior to reaching the consumer significantly affects

its composition.


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CHAPTER ONE

INTRODUCTION

1.1 Background

Honey is a sweet, thick and viscid fluid collected from beehives and usually found in cells

of the honey comb. It is produced from nectar collected from various flowers by honey

bees and processed. Among the important uses, pure and undiluted honey serves as natural

sweetener and contains a broad variety of vitamins for human consumption (Dustmann,

1993). Food authenticity is of great economic significance for the sectors involved in food

production, marketing and for the consumers, who are looking for guaranteeing the quality

of their food. Honey cannot be an exception in this case (Chalhoub et al., 2007). To ensure

that the consumer rips the intended benefit of honey consumption, the quality of the honey

with regard to its elemental composition and some physicochemical parameters should be

assessed.

Honey has a lot of health benefits for toddlers and children. It helps in faster wound healing,

offers liver protection, sustains energy for longer periods of time and controls cough in

children. It is also used for therapeutic, nutritional, medicinal and cosmetic purposes

(Ajibola et al., 2012). For instance, it is used as an ingredient in numerous manufactured

foods, mainly in cereal based products, for its sweetness, colour, flavour, caramelization,

and viscosity (de Rodrı´guez et al., 2004).

In addition to the vitamins and minerals, honey also contains other substances necessary to

sustain life, including enzymes, proteins, amino acids, minerals, trace elements, aromatic


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compounds, polyphenols, and water. It also contains “pinocembrin”, an antioxidant

associated with improved brain functioning. In general, honey contains approximately 70

- 80% sugar, mainly from fructose and glucose (Kucuk et al., 2007; Karaman et al., 2010).

Some of the components in honey are due to the maturation process, which are added by

the bees whiles others are derived from the plants, which in turn, absorb several

components from the environment such as soil, air and water.

Honey is an excellent and widely used food that is popular all over the world. As a result

of its good properties (anti-inflamatory, curative, medicinal and nutritional), honey is

consumed globally. The colour and flavour of honey differ depending on the nectar source.

In general, lighter coloured honeys are mild in flavor, while darker honeys are usually more

robust in flavor. The consumption of honey also differs strongly from country to country.

At present the annual world honey production is about 1.2 million tones, which is less than

1% of the total sugar production. In Africa, though reliable production and trade statistics

on honey do not exist, it is believed that the consumption of honey on the continent far

exceeds production (FAO, 2003).

Due to the variation of botanical and geographical origin, honey differs in appearance,

sensory, perception consistency, characteristics and composition. Its composition and

quality is affected by several environmental factors during production such as weather and

humidity inside the hive, nectar conditions and treatment of honey during extraction,

treatment and storage. The composition of honey even varies with the type of food bees

feed on (Guler et al., 2007).


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Minerals or elemental content seem to be good indicators for a classification system of

honey, mainly because they are stable. Bees are estimated to forage on plants growing in a

relatively large area of more than 7 km2. It is because of this large forage area that honey

bees and their products have been proposed as suitable bio-indicators of chemical pollution

(Tuzen et al., 2007). It is known that different unifloral honeys contain varying amounts of

minerals and trace elements (Yilmaz et al., 1999). From the nutritional point of view,

chromium, manganese and selenium are important, especially for children. The elements;

sulphur, boron, cobalt, fluoride, iodide, molybdenum and silicon can be important in

human nutrition too, although there are no recommended daily intake values proposed for

these elements (Bogdanov et al., 2008).

The evaluation of heavy metals content in honey has a two-fold significance: the toxicity

of these metals and the consequent necessity to develop adequate analytical procedures for

their monitoring (Tong et al., 1975).

Honey can be characterized based on its chemical, physical or biological properties.

Physicochemical parameters such as electrical conductivity, specific gravity, water

content, free acid and pH can all be used as criteria for characterizing honey (Gomes et al.,

2010). The electrical conductivity of the honey is closely related to the concentration of

mineral salts, organic acids and proteins; and has proved useful for discriminating honeys

of different floral origins (Acquarone et al., 2007). Most honeys are acidic in nature with

low pH between 3.1 and 6.1. This value could be due to the presence of some weak organic


4

acids primarily gluconic acids, ascorbic acid and even acetic acid. This relatively acidic pH

level prevents the growth of many bacteria (Cui et al., 2008; Kebede et al., 2012).

In this study, elemental composition of honey was monitored from some regions of Ghana.

The monitoring was done on the farmer-to-trader routes to ascertain how botanical origin

and subsequent handling of honey affects its composition prior to reaching the consumer.

1.2 Statement of the Problem

According to the Food and Agricultural Organisation (FAO, 2012), it does not matter

where bees are living – in their own nest built in the wild or in any type of hive – bees

always store clean and perfect honey. The place where bees live has no effect upon the

quality of honey they make. It is only subsequent handling by humans that leads to

reduction in quality.

The type of equipment used to extract honey as well as the quality of the equipment used

to store honey after harvesting are possible sources of honey contamination. For example,

storing honey in galvanize containers can be a major source of zinc contamination

(Bogdanov et al., 2003).

For the uninformed consumer, the important features of honey are its aroma, flavour,

colour and consistency, all of which depend upon the species of plants being foraged by

the bees. However, these factors are not enough in ascertaining the quality of honey. This


5

is because literature has shown that honey content can vary greatly even within one nation,

let alone between regions and continents (Bibi et al., 2008). Importantly, there is inadequate

published information on the quality and elemental composition of Ghanaian honey.

Ghanaian honey may therefore not be as “pure” as it is always proclaimed by beekeepers

and retailers. It is therefore necessary to do a comprehensive assessment of Ghanaian honey

to ascertain its quality.

In this study, honey samples were collected from farmers and traders in the Brong Ahafo,

Ashanti, and Greater Accra regions of Ghana and monitored along the farmer-to-trader

channels. This was done in order to trace the levels of elemental compositions. The levels

of selected toxic heavy metals (Hg, Pb, Cd, As, V) and essential metals (K, Na, Mn, Al,

Ca, Mg, Fe, Cr, Co, Cu) in the samples were analysed using instrumental neutron activation

analysis and atomic absorption spectroscopy. A physicochemical study was done prior to

metal content analysis of honey.

1.3 Objectives of the Study

1.3.1 General Objective

The study endeavours to assess the quality of honey produced from various regions in

Ghana with respect to variation in elemental composition along farmers-to-traders route.

1.3.2 Specific Objectives

In achieving the primary objective, the following specific objectives were pursued;


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a. To evaluate the variation of trace element content in honey from production on the

farm to the market.

b. To investigate the sources of contamination of trace elements and heavy metals in

honey.

c. To investigate how botanical and geographical origin affects the composition of

Ghanaian honey.

d. To generate a useful baseline data for comparative analysis of the elemental levels

of Ghanaian honey with respect to national and international compositional

standards of honey specifications.

1.4 Relevance and Justification

According to the FAO (2012), honey is not a simple commodity with a single, standard

composition. It is a product that is harvested and marketed in nearly every country, yet

there is no single international standard for honey quality. Nations and market regions set

their own criteria for honey, defining what honey is, and what its composition should be.

The metal composition is geographically significant, as the majority of metals in honey are

transferred from the soil to the plant or flower from which the nectar is collected. Metals

can also be transferred from other sources such as water aerosol spray and atmospheric

pollution. Heavy metals and high concentration levels of essential metals can be toxic both

to man and animals. For example, extensive exposure to zinc chloride can cause respiratory

disorders (Saeed, 1998). Rapid increase in industrialization in Ghana can also lead to

environmental pollution, hence the possibility of increase of these metals in honey.


7

When the toxic heavy metals present in honey are above the permissible levels, they are

threats to humans, through the possible negative effect of the contaminants. It has been

reported that lead can cause damage of brain, kidney, nervous system and red blood cells.

Other problems caused by heavy metals include metabolic anomalies, respiratory

disorders, nausea and vomiting (Hase, 1973; Wotton, 1976, 1978).

In the recent past, news about “contaminated honey” has been circulated by the mass

media. The most recent example is the news about Ghanaian honey diluted with white

sugar and other additives. (www.modernghana.com/generalnews/fakehoneysoldinGhana,

12th March, 2014, 13:56 CET). Such messages will damage the good image of honey.

Thus, it is of utmost importance for beekeepers and retailers to localise and rid honey of

different contamination sources.

The results of physical and chemical measurements and analyses touch on practically every

aspect of modern life. People demand proof that foodstuffs are not adulterated. They feel

threatened by environmental pollution when they cannot perceive pollutants directly with

their own senses and instead picture in their imagination food, water, soil, and air quality

based on a system of threshold values and analytical results. Even our own bodies become

the object of analytical examination when, whether preventatively or in case of actual

illness, we undergo clinical diagnosis (Funk et al., 2007).

Beekeepers and processors in Ghana continue to rely heavily on their own experience and

observation to determine whether their products meet consumer’s expectations. Regarding

quality issues, majority of Beekeepers across the country indicated that their packaged


http://www.modernghana.com/generalnews/fakehoneysoldinGhana

http://www.modernghana.com/generalnews/fakehoneysoldinGhana

8

honey for the market is not certified or analysed. The only test for honey quality in most

cases is based on traditional methods, visual colour and viscosity (thickness). The

elemental profile of honey is therefore significantly three main reasons – for evidence of

provenance, nutritional benefit and toxicological implications.

This research work monitored the composition of Ghanaian honey along the farmer-to-

trader routes to ascertain its quality. The knowledge will be transferred to the bee farmers

and retailers, so that they can produce and sell “clean” bee products respectively. The

findings will also be used to advice beekeepers and retailers on the best ways to handle

their products to reduce the level of contamination. It will also serve as guidelines for some

industries and organizations in formulating policy decisions.

1.5 Scope and Delimitation

Once harvested, honey does not require further processing. On a small scale, simple

equipment as used in other forms of food preparation is adequate: plastic buckets, bowls,

sieves, straining cloths and containers. Honey is a stable commodity with a long shelf life:

if harvested carefully and stored in containers with tight-fitting lids, it will remain

wholesome for several years (FAO, 2012).

This study assesses whether the various processes honey goes through, before it reaches

the consumer affects its composition, and if it does, by how much. The work was carried

out in three of the largest honey producing regions in Ghana (Brong Ahafo, Ashanti, and


9

Greater Accra). The results were compared with what other researchers have published in

Ghana and elsewhere in the world. Instrumental neutron activation analysis (INAA) and

atomic absorption spectrometry (AAS) were used as analytical techniques. INAA method

has several advantages which include; high sensitivity, high precision and accuracy, little

or no elaborate sample preparation, non-destructive and give multi-element capability. For

the AAS technique, sample preparation is generally simple and frequently involves little

more than dissolution in an appropriate acid. The instrument is also easy to tune and

operate. Elements of interest are trace elements and heavy metals because of their toxicity,

health reasons, honey’s quality assessment, and environmental pollution monitoring.


10

CHAPTER TWO

LITERATURE REVIEW

2.1 Definition of Honey

Honey is the natural sweet substance produced by honey bees from the nectar of plants or

from secretions of living parts of plants (CODEX, 2001). Honey can also be produced from

excretions of plant sucking insects on the living parts of plants, which honey bees collect,

transform by combining with specific substances of their own, deposit, dehydrate, store

and leave in the honey comb to ripen and mature (CODEX, 2001).

The two types of honey are:

a) Blossom honey or nectar honey

Honey which comes from nectars of plants.

b) Honeydew honey

Honey which comes mainly from excretions of plant-sucking insects

(Hemiptera) on the living parts of plants or secretions of living parts of

plants (CODEX, 2001).

2.2 Composition of Honey

Honey consists essentially of different sugars, predominantly fructose and glucose as well

as other substances such as organic acids, enzymes and solid particles derived from honey

collection. The colour of honey varies from nearly colourless to dark brown. The

consistency can be fluid, viscous or partly to entirely crystallised. The flavour and aroma

vary, but are derived from the plant origin (CODEX, 2001).


11

Honey may be composed of multiple materials. In addition, honey is one of the most

complex mixtures of carbohydrates produced in nature. In common honey, mono- and di-

saccharides constitute 80–85% (w/w), water is around 15–20% (w/ w) and other organic

compounds and inorganic ions being present to a minor extent (Sanna et al., 2000).

However, the minor components are often of great importance from many points of view.

Honey contains varying amounts of mineral substances, ranging from 0.02 to 1.03 g/100g.

Potassium, with an average of about one third of the total, is the main mineral element, but

there is a wide variety of trace elements (White, 1975).

Research conducted by Bogdanov et al., (2008) at the Swiss Bee Research Centre

(Switzerland) validated the average composition of the nutrients in honey. The overall

composition of honey analyzed is shown in Table 2.1. The carbohydrates were the main

constituents, comprising about 95% of the honey dry weight. Beyond carbohydrates, honey

contains numerous compounds such as organic acids, proteins, amino acids, minerals,

polyphenols, vitamins and aroma compounds. However, it should be noted that the

composition of honey depends greatly on the botanical origin, a fact that has been seldom

considered in the nutritional and physiological studies (Persano and Piro, 2004).


12

Table 2.1: Honey Composition (data in g/100 g)

Souce: Bogdavov et al., (2008)

The specific mineral composition of honey, as analyzed by White (1975) and Conti (2000)

include: sodium 1.6-17 g/100g, calcium 3-31 g/100g, potassium 40-3500 g/100g,

magnesium 0.7-13 g/100g, phosphorus 2-15 g/100g, zinc 0.05-2 g/100g, copper 0.02-0.6

g/100g, iron 0.03-4 g/100g, manganese 0.02-2 g/100g, chromium 0.01-0.3g/100g,

selenium 0.002-0.01 g/100g.

Other trace elements in honey (mg/100g) also include: aluminium 0.01-2.4, arsenic 0.014

- 0.026, barium 0.01-0.08, boron 0.05 - 0.3, bromine 0.4 - 1.3, cadmium 0 - 0.001, chlorine

0.4 - 56, cobalt 0.1 - 0.35, fluorine 0.41.34, iodine 10-100 (Terrab et al., 2004).

Honey composition Blossom honey Honey dew

Average Range Average Range

Water

Monosaccharides

Fructose

Glucose

Disaccharides

Sucrose

Others

Trisaccharides

Melezitose

Erlose

Others

Undetermined oligosaccharides

Total sugars

Minerals

Amino acids, proteins

Acids

17.2

38.2

31.3

0.7

5.0

<0.1

0.8

0.5

3.1

79.7

0.2

0.3

0.5

15-20

30-45

24-40

0.1-4.8

2-8

0.5-6

0.5-1

0.1-0.5

0.2-0.4

0.2-0.8

3.5-4.5

16.3

31.8

26.1

0.5

4.0

4.0

1.0

3.0

10.1

80.5

0.9

0.6

1.1

15-20

28-40

19-32

0.1-4.7

1-6

0.3-22.0

0.1-6

0.1-6

0.6-2.0

0.4-0.7

0.8-1.5

4.5-6.5


13

2.3 Production of Honey by Bees

Bees make honey from the nectar that they collect from flowers. Plant saps and honeydew

are also used to a minor extent. Forager honeybees are always female worker bees. After

visiting a flower, the foraging honeybee flies back to its nest that may be in a hollow tree

or other natural cavity, or inside a man-made hive. The nectar that it collected is carried in

its honey sac, a modified part of the gut (FAO, 2012).

Once inside the nest, it regurgitates the fluid and passes it through its mouth to one or more

'house' bees, which in turn swallow it and regurgitate it. As each bee sucks the fluid up

through its proboscis and into its honey sac, a small amount of protein is added while water

is evaporated. The proteins are enzymes, which convert sugars in the nectar into different

types of sugars (FAO, 2012). The liquid travels through a chain of bees in this way before

it is placed in a cell of honeycomb. After the liquid has been placed in the cell, bees

continue to process it, and further water evaporates as they do so (FAO, 2012).

The temperature of the nest near the honey storage area is usually around 35 °C. This

temperature, and the ventilation produced by fanning bees, causes further evaporation of

water from the honey. When the water content is less than 20%, the bees seal the cell with

a wax capping: the honey is now considered 'ripe' and will not ferment. The bees have

prepared for themselves a concentrated food store, packed in minimal space that can be

stored until they need it during any future period when there are no flowers, for example

winter periods. The honey is produced and stored in such a way that it will not significantly


14

deteriorate in quality – it will not go mouldy, and there will be no problem of fermentation

during storage (FAO, 2012).

2.4 Classification of Honey

Several ways of classifying honey based on its source, mode of extraction, flavor, colour,

consistency and origin have been proposed by different organizations.

According to the US Department of Agriculture (CODEX, 2001), honey can be classified

as;

Liquid honey: honey that is free of visible crystals.

Crystallized honey: honey that is solidly granulated, irrespective of whether

candied, fondant, creamed, or spread.

Partially crystallized honey: honey that is a mixture of liquid honey and

crystallized honey.

Filtered honey: honey of any type that has been filtered to the extent that all or

most of the fine particles, pollen grains, air bubbles, or other materials normally

found in suspension, have been removed.

Strained honey: honey of any type that has been strained to the extent that most

of the particles, including comb, propolis, or other defects normally found in

honey have been removed. Grains of pollen, small air bubbles, and very fine

particles would not normally be removed.


15

2.5 Nutritional and Health Benefits of Honey

Honey has enormous benefits. Some of its nutritional and health benefits for toddlers,

children and adults include sustained energy for longer period of time, as a sweetener, skin

care, cough suppressant and source of antioxidants (NHB, 2015).

2.5.1 Energy Food

Honey is a source of carbohydrates, providing 17 grams of carbohydrate per tablespoon,

which makes it ideal for working muscles since carbohydrates are the primary fuel the body

uses for energy. Carbohydrates are necessary in the diet to help maintain muscle glycogen,

also known as stored carbohydrates, which are the most important fuel source for athletes

to help them keep going. When honey is eaten before a workout or athletic activity, it is

released into the system at a steady rate throughout the event. Consuming carbohydrates,

such as honey, during a workout helps the muscles stay nourished longer and delays fatigue

(NHB, 2015).

2.5.2 Sweetener

Honey is slightly sweeter than sugar, so less can be used to achieve the same sweetness

intensity. It contains different types of sugar; glucose, sucrose and fructose. When taken,

these sugars are easily digested, and enters the blood stream easily. They supply energy for

longer durations. As a flavor, it does not only imparts a unique flavor to any dish, but it

also balances and enhances the flavor profiles of other ingredients used in a recipe. Honey

acts as a binder and thickener for sauces, dressings, marinades and dips. As a humectant,


16

it provides and retains moisture to a variety of dishes and can even extend the shelf life of

baked goods (NHB, 2015).

2.5.4 Skin Care

Honey is a humectant, which means it attracts and retains moisture. This makes honey a

natural fit in a variety of moisturizing products including cleansers, creams, shampoos and

conditioners. Manufacturers have used honey in everything from hand lotions and

moisturizers to bar soaps and bubble baths. One reason they use honey is for its

wholesomeness (NHB, 2015)

2.5.5 Cough Suppressant

Honey has been used for centuries to help alleviate some of the symptoms associated with

a common cold. In the year 2007, a study by Penn State College of Medicine research team

found that honey may offer parents an effective alternative to over-the-counter cough

medicine. The study found that a small dose of buckwheat honey given before bedtime

provided better relief of nighttime cough and sleep difficulty in children than no treatment

or dextromethorphan, a cough suppressant found in many over-the-counter cold

medications (NHB, 2015). Apart from irritating cough, honey is also useful in reducing

difficulties associated with swallowing (Ashkin et al., 2013).

2.5.6 Source of Antioxidants

Antioxidants are chemicals that block the activity of other chemicals known as free

radicals. The presence of free radicals and reactive oxygen species are culpable in the


17

processes of cellular dysfunction, pathogenesis of metabolic and cardiovascular diseases

as well as aging. The consumption of foods and substances rich in antioxidant can protect

the body against these pathological changes and consequently prevent the pathogenesis of

these and other chronic ailments. Researches indicate that honey contains several important

compounds, and these include antioxidants (Al-Waili, 2003; Schramm et al., 2003). The

colour of honey also influences its antioxidant content, as darker honeys are known to have

higher amount than lighter honeys (Frankel et al., 1998; Ajibola et al., 2012).

2.5.7 Children Nutrition

There are anecdotal evidences encouraging the feeding of honey to new born babies by

some customs and traditions. It is now an established fact that feeding honey to infants will

improve memory and growth, reduce anxiety and enhance the children’s performance in

later life. In 2009, Chepulis and coworkers gave scientific credence to this beneficial

practice in behavioural study in animals (Chepulis et al., 2009). They fed 8 weeks old rats

with diet supplemented with either honeydew honey or sucrose, and control group with

sugar-free diet. These workers noted improved spatial memory and reduced anxiety in the

honey-fed rodents better than the other groups over the twelve months trial period. The

authors concluded that early introduction of honey diet is beneficial and can improve

memory loss and cognitive decline associated with aging (Chepulis et al., 2009; Ajibola et

al., 2012). Honey contains several amino acids and vitamins that are very good for physical

development of children.


18

2.6 The Honey Industry in Ghana

2.6.1 Traditional Test for Determining the “Purity” of Honey

Information obtained through interaction with the honey farmers in the three regions

chosen for the study revealed some traditional methods usually used to test for “pure”

honey. As a way of determining whether water, glucose or any additives have been added

to honey, most traders and consumers of honey in Ghana employ any of these simple tests.

However, these tests are not sufficient enough to ascertain the wholesomeness and quality

of honey, especially with regard to its elemental composition.

Dissolution test: Put a teaspoonful of honey into a glass of water. If the honey does

not dissolve at the bottom of the glass, it is likely “pure” honey

Absorption test: Put a drop of honey on some cotton cloth or a piece of low-grade

paper. If the honey spreads on the paper or seeps through, then it is not “pure”

honey.

Wash test: Put a drop of honey on a cloth and wash it. If there is a stain left, then

it is most likely “fake” honey.

Water content test: There is very little water in honey. Fake honey has higher

water content. Take a piece of bread and put it in the honey. If the bread hardens,

then the honey is most likely “pure”. However, if the bread softens or falls apart

then the honey has additives.

Dip test: Dip a cotton pad or the cotton wick of a candle into a bit of honey, and

shake off the excess. Attempt to light the cotton pad or wick. If it burns easily, then

it probably has no added water but may or may not have other substances added. If

it does not burn or it makes a cracking sound, water may have been added.


19

2.6.2 Production Levels and Trends

Although, information on the sub-sector is insufficient, it has been observed that honey

production throughout the country has been increasing annually (Table 2.2). For example,

in the Greater Accra region, honey production levels doubled from 7,400 kg in 2004 to

15,300 kg in 2008. Production levels of honey in the Central region increased by about

207%, from 17,900 kg in 2004 to 54,800 kg in 2008. However, in 2007 there were no data

available for production levels of honey in Eastern and Volta regions (SNV Ghana, 2010).

Total honey production in all regions increased from 236,795 kg in 2007 to 428,836 kg in

2008.

Table 2.2: Estimated Production Levels of Honey in Ghana

REGION Total Production (kg)

2007 2008

Greater Accra 11500 15300

Western 20 600 42 900

Central 52 400 54 800

Brong Ahafo 65 205 74 088

Ashanti 46 536 51 961

Eastern - 43 000

Northern 27 727 29 834

Volta - 94 000

Upper West 12 397 12 222

Upper East 10 430 10 731

TOTAL 236 795 428 836

Source; (SNV Ghana, 2010).


20

The production of beeswax is directly linked to honey production, averaging about 14% of

honey produced. Total bee wax production, therefore, increased from 34,552 kg in 2007 to

60,031 kg in 2008. There are a total of about 52,883 beehives in production in the 10

regions. The Volta region has the highest number of beehives (24,065), followed by

Eastern region (8,000) and Central region (5,400) (SNV Ghana, 2010).

The national average holding is about five beehives per Beekeeper. Based on the number

of beehives and production levels, average annual yield per hive is greater in the Brong

Ahafo (34 kg) and Ashanti (23 kg) regions. The national average yield per hive is about 14

kg per annum (Aidoo, 2005).

In 2008, Ghana’s traditional honey production yield was estimated to be 428 836 kg in one

harvesting season and is growing between 2% and 3% per annum. Based on production

levels and number of hives, the average yield per hive is about 14 kg. However, the yields

per hive in Western region (15 kg), Brong Ahafo (34 kg) and Ashanti (23 kg) regions were

higher compared to Eastern (5 kg) and Volta (4 kg) regions (SNV Ghana, 2010). The

gender distribution of Beekeepers in all ten regions of Ghana is presented in Figure 2.1.

This study was done in Brong Ahafo, Ashanti and Greater Accra regions where most of

the Ghanaian honey are produced.


21

Figure 2.1: Gender distribution of beekeepers in Ghana (Source: SNV Ghana, 2010)

2.7 Possible Contaminants and Toxic Compounds in Honey

Honey and bee products have the characteristic of being natural, healthy and clean. But

like any other natural food, honey can also be contaminated. This may primarily be due to

the fact that bee products are produced in an environment, polluted by different sources of

contaminants. The main sources of contaminants within the environment, and from

beekeepers are heavy metals, pesticides, antibiotics, radioactivity, bee repellents during

honey harvest (Bogdanov, 2006).

2.7.1 Heavy Metals

The United States Environmental Protection Agency (US EPA, 2011) defines heavy metals

as “any metallic chemical element that has a relatively high density (superior to 5 g/cm3);

most of which are toxic or carcinogenic even at low concentrations, can damage living

0

500

1000

1500

2000

2500

3000

3500

4000N

um

ber

of

bee

kee

per

s

Region

Gender Distribution of beekeepers in Ghana

Male Female


22

things and tend to accumulate in the food chain: example mercury, cadmium, arsenic, lead

and chromium”.

The fundamental aspect that differentiates heavy metals from other pollutants, like

pesticides, is their introduction into the environment and their environmental fate. Heavy

metals are released in a continuous manner into the environment by various natural and

anthropogenic sources. They do not decay and are characterized by latent toxicity. They

are continuously present in the environment and enter into the biological cycles (Porrini,

et al., 2003). They are predominately transferred as molecules or particulate matter via the

atmosphere, mostly on a large scale. The amounts of anthropogenically derived heavy

metals have increased continuously since the beginning of the industrial revolution

(Komarnicki, 2005). Generally, they do not cause honeybee mortality, but they can be

deposited on the body hairs and taken back to the hive with the pollen, or they might be

absorbed together with the nectar of the flowers, or through the honeydew produced by

aphids (Ruschioni et al., 2013). Air and soil contain heavy metals, mainly from industry

and traffic which can also contaminate the bee colony and its products.

2.7.2 Classification of Heavy Metals Based on Their Importance

Heavy Metals can be classified into two major groups based on their importance;

I. Essential: these are metals vital to at least some organisms (micronutrients). They

are Cu, Co, Ni, Fe, Zn and Mn. Micronutrients helps in the regulation of osmotic

pressure, redox processes and enzyme co-factors. They are also significant in the

preservation of protein structure (Vallee and Auld, 1990). For instance, Zn is an


23

essential co-factor for numerous enzymatic reactions in the human body. Similarly,

Mg and Cu are all trace elements, which are vital in human diet. However, even

essential metals such as Zn and Cu are toxic at high concentrations (Sedgwick,

2005).

II. Non-essential: these heavy metals have no known biological functions. Metals

such as Cd and Pb do not play any known physiological function, and are, in fact,

toxic to cells (Denton et al., 2001). Cd is extremely toxic and has been shown to

induce DNA breakage, while Pb reacts with the Sulphydryl groups of proteins and

restrains their function (Ron et al., 1992).

2.7.3 Occurrence and Toxicity of Selected Heavy Metals

2.7.3.1 Arsenic (As)

Arsenic is present in the environment as a naturally occurring substance or as a result of

contamination from human activity. It is found in water, air, food, and soil in organic and

inorganic forms. There are over 150 arsenic-bearing minerals (Carapella, 1992). Food is

typically the largest source of exposure to arsenic. The largest sources are seafood, bee

products, rice and some rice products, mushrooms and chicken. Arsenic concentrations in

food typically range from 20 - 140 µg/kg. Its concentration in the earth’s crust is 1.8 mg/kg

(Taylor, 1964).

US EPA (2011) reports that, ingesting lower doses can cause irritation of the digestive

tract, decreased blood cell production, fatigue, abnormal heart rhythms, damage to blood


24

vessels, and/or a pins-and-needles feeling in hands and feet. Ingesting inorganic arsenic

over long periods affects the skin. Breathing high levels of inorganic arsenic may cause

sore throat, lung irritation, and lung cancer. U.S. EPA's IRIS database classifies inorganic

arsenic as a human carcinogen. It notes increased lung cancer mortality from inhalation

exposure, increased mortality from cancers of the liver, kidney, lung, and bladder due to

ingestion of inorganic arsenic in drinking water, and an increased incidence of skin cancer

due to consumption of drinking water or food containing inorganic arsenic. The

International Agency for Research on Cancer (IARC, 1980) has determined that arsenic

and inorganic arsenic compounds are carcinogenic to humans.

2.7.3.2 Lead (Pb)

As reported by the ATSDR (1999), U.S. Department of Health and Human Services, lead

is a toxic substance present in our environment in small amounts and everyone is exposed

to some lead from daily actions such as inhaling dust, eating food, or drinking water.

Human activities (such as use of "leaded" gasoline) have spread lead and substances that

contain lead to all parts of the environment. For example, lead is in air, drinking water,

foods (not excluding honey), rivers, lakes, oceans, dust, and soil. Lead is also in plants and

animals that people may eat. Other sources of lead released to the air include burning fuel,

such as coal or oil, industrial processes, and burning solid waste.

Lead gets into foods from dust that contains lead falling onto them during processing. Lead

may also enter foods if they are put into improperly glazed pottery and from leaded-crystal

glassware. Shortly after lead gets into the body, it travels in the blood to the soft tissues,


25

(such as the liver, kidneys, lungs, brain, spleen, muscles, and heart). Lead, contained in the

air and originating mainly from motor traffic can contaminate air and then directly nectar

and honeydew. Generally, Pb is not transported by plants. The main target for lead toxicity

is the nervous system, both in adults and in children. Lead exposure or injection may cause

weakness in fingers, wrists, or ankles. Lead exposure may also cause anemia, a low number

of blood cells. At high levels of exposure, lead can severely damage the brain and kidneys

in adults or children. In pregnant women, high levels of exposure to lead may cause

miscarriage. High-level exposure in men can damage the organs responsible for sperm

production (ATSDR, 1999).

2.7.3.3 Cadmium (Cd)

Cd is an element that occurs naturally in the earth's crust. Cd is not usually found in the

environment as a metal. Cd is typically present as complex oxides, sulfides, and carbonates

in Zn, Pb and copper ores (Finkelman, 2005). Spills and leaks from hazardous waste sites

can also cause cadmium to enter soil, water or foods, including bee products depending on

the location of apiaries. The average Concentration of Cd in the earth’s crust is 0.2 mg/kg

and it occurs in soil from 0.1 to 0.5 mg/kg (Taylor, 1964). Food is one of the potential

sources of cadmium exposure for members of the general population. Only a small portion

of Cd might reach honey by air, mainly in the vicinity of incinerators. The major sources

of Cd include waste from municipal effluents, sewage sludge and mine waste,

metallurgical; industries, fossil fuels, and some phosphorous containing fertilizers (Denton

et al., 2001). Eating food or drinking water with very high Cd levels severely irritates the

stomach, leading to vomiting and diarrhea (Young, 2005). Eating small amounts of Cd


26

over a long period of time can lead to a build-up of cadmium in the kidneys. This Cd build-

up causes kidney damage, and also causes bones to become fragile and break easily (Goyer,

1991). The U.S. Department of Health and Human Services has determined that Cd and

Cd compounds may reasonably be anticipated to be carcinogens.

2.7.3.4 Chromium (Cr)

Cr is one of the most abundant heavy metals in the lithosphere (Callender, 2003). Cr (III)

occurs naturally in the environment and is an essential nutrient required by the human body

to promote the action of insulin in body tissues so that sugar, protein, and fat can be used

by the body. The average concentration of Cr in the earth crust is 100 mg/kg (Taylor, 1964).

Various methods of processing, storage, and preparation can alter the chromium content of

food. Cr (III) is an essential nutrient that helps the body use sugar, protein, and fat. An

intake of 50 to 200 µg of Cr (III) per day is recommended for adults. Because some Cr (VI)

compounds have been associated with lung cancer, the Department of Health and Human

Services has determined that certain Cr (VI) compounds are known carcinogens. Exposure

to Cr (VI) salts for a period of 2-26 years will cause cancer of the digestive tract

(Finkelman, 2005).

2.7.3.5 Mercury (Hg)

Mercury is a chemical (element) that occurs naturally in the environment in several forms.

Mercury can combine with other elements, such as chlorine, carbon, or oxygen, to form

mercury compounds. All forms of mercury are considered poisonous. Because mercury

occurs naturally in the environment, everyone is exposed to very low levels of mercury in


27

air, water, and food (including honey). The U.S. Food and Drug Administration (FDA) has

estimated that, on average, most people are exposed to about 50 ng of mercury per kilogram

of body weight per day in the food they eat.

People who eat foods (including honey) containing organic mercury can have permanent

damage to the brain, kidneys, and the growing fetus. There is no information to show that

mercury causes cancer in humans or animals (ATSDR, 1992).

2.7.3.6 Copper (Cu)

Copper is a reddish metal that occurs naturally in rock, soil, water, sediment, some foods

and air. Its average concentration in the earth's crust is about 55 mg/kg, and in soil it is 15

g/kg soil (Taylor, 1964). It is an essential element for all known living organisms including

humans and other animals. Copper is common in the environment. One may be exposed to

copper by breathing air, drinking water, eating food, and by skin contact with soil, water,

and other copper-containing substances. Food (including honey) naturally contains copper.

A person eats and drinks about 1 mg of copper every day. Copper is necessary in diets for

good health. Copper rapidly enters the bloodstream and is distributed throughout the body

after eating or drinking it. Callender, (2003) reported that that the adsorption behavior of

Cu in natural systems is strongly dependent on the type and concentration of inorganic and

organic ligands.

Copper is necessary for good health. However, very large single or daily intakes of copper

can harm one’s health. Intentionally high intakes of copper can cause liver and kidney


28

damage, nausea, stomach cramps and even death (Kegley et al., 2009; MDH, 2006). Very

young children are sensitive to copper, and long-term exposure to high levels of copper in

food or water may cause liver damage and death. Copper is not known to cause cancer.

2.7.3.7 Zinc (Zn)

Zinc is a naturally-occurring element. Pure zinc is a metal, and in combination with other

elements is a widespread and common part of the earth's crust. Zinc is a minor but essential

nutrient: too little can lead to reproductive, immune, and other health problems. On the

other hand, too much zinc can be poisonous. Zinc enters the air, water, and soil as a result

of both natural processes and human activities.

According to US EPA's IRIS database, it is not currently possible to tell whether zinc

exposure causes cancer in humans. Large doses of taken by mouth, even for a short time,

can cause stomach cramps, nausea, and vomiting. Ingesting high levels of zinc for several

months may cause anemia, damage the pancreas, and decrease levels of high-density

lipoprotein (HDL) cholesterol (Finkelman, 2005).

2.7.3.8 Manganese (Mn)

Manganese does not occur in the environment as the pure metal. Rather, it occurs combined

with other chemicals such as oxygen, sulfur, and chlorine (NAS, 1973). Because

manganese is a natural component in the environment, people are always exposed to low

levels of it in water, air, soil, and food. Its average concentration in the earth's crust is about

950 mg/kg (Taylor, 1964).


29

Eating a small amount of manganese each day is important in maintaining one’s health.

The amount of manganese in a normal diet (about 2,000-9,000 µg/day) seems to be enough

to meet a person’s daily need, and no cases of illness from eating too little manganese have

been reported in humans. Too much manganese, however, can cause serious illness.

Although there are some differences between different kinds of manganese, most

manganese compounds seem to cause the same effects, which may include mental and

emotional disturbances, brain injury, slow and clumsy body movements and so on. Toxic

exposures occur mainly due to particulate material in the air from mining and industrialized

activities (Francis and Forsyth, 2005). Symptoms of manganese poisoning are

hallucinations, forgetfulness, and nerve damage. Manganese can also cause Parkinson’s

disease, lung embolism and bronchitis (Lenntech, 2011).

2.7.3.9 Vanadium (V)

Vanadium is a compound that occurs in nature as a white-to-gray metal, and is often found

as crystals. It usually combines with other elements such as oxygen, sodium, sulfur, or

chloride. Vanadium and vanadium compounds can be found in the earth's crust, with an

average of about 135 mg/kg and in rocks, some iron ores, and crude petroleum deposits.

Vanadium mainly enters the environment from natural sources and from the burning of

fuel oils. It combines with other elements and particles and can find their way into certain

foods including honey (ATSDR, 1999).


30

It is not yet known, the health effects in people of ingesting vanadium. The health risks

associated with exposure to vanadium are dependent on its oxidation state. An intake of

over 10 mg of V per day can be toxic for adults; the source is usually airborne

anthropogenic V (WHO, 1996). Some animals that ingested vanadium over a long term

had minor kidney and liver changes. The Department of Health and Human Services, the

International Agency for Research on Cancer, and the EPA have not classified vanadium

as to its human carcinogenicity.

2.7.3.10 Cobalt (Co)

Co does not exist naturally as a base metal, but it is a constituent of more than 70 naturally

occurring minerals. The most common cobalt minerals are arsenosulfide, arsenide and

sulphide (IARC, 1991). The average concentration of Co in the earth crust is about 25

mg/kg. Sources of Co are both natural and anthropogenic (Barceloux, 1999). The mobility

of Co is moderately high and is limited in early stages by co-precipitation with limonite

and MnO2. As pH decreases, adsorption of Co by particulate matter also decreases, since

H+ concentrations compete with metal binding sites. Therefore, levels of dissolved Co will

be increased at low pH (ATSDR, 2004).

Cobalt is used in the treatment of anaemia in pregnant women, because it stimulates the

manufacture of red blood cells (ANL, 2005). Cobalt is Valuable for humans because it is

part of Vitamin B12, which is essential for human health elevated concentrations may result

in serious liver and kidney damage, gastrointestinal distress and, on a lesser scale, vomiting

and nausea (Virkutyte and Silampaa, 2006).


31

The effects of the heavy/trace metals on humans is presented in Table 2.3.

Table 2.3: The Toxicity of Certain Heavy/Trace Metals to Humans

Heavy metals/Trace element

Effects on Humans

As, Cd, Hg, Pb, U

As, Pb

As, Bi, Cu, Cr, Fe, Mn, Sb

As, Bi, Pb

As, Hg, Mn, Pb, Ti

As, Cr, Hg

Pb, Hg

As, Be, Cd, Cr, Ni, U

Impair the function of the kidney

Impair the function of hematopoiesis system

Impair liver function

Cause illness of the heart – circulatory system, or illnesss

of the respiratory system

Cause damage of the central and peripheral nervous

system

Cause mutagenicity

Cause teratogenicity

Cause human carcinogens

Source: Merian (1984) and Geldmacher et al., (2004)

2.8 Studies on the Composition of Honey

The mineral, nutritive, medicinal and chemical or elemental compositions of honey have

been of considerable interest for both man and animals. In view of this, qualitative and

quantitative analysis of the elements in honey is of great importance to many research

groups.


32

Research has been carried out in many countries to determine the mineral composition of

honey. For instance, using atomic absorption and emission spectroscopy honey samples

collected from different parts of Kenya were analysed (Mbiri et al., 2011) to determine the

levels of selected heavy metals (Pb, Cd, Zn, Cu, As) and essential metals (K, Na, Ca, Mg,

Fe). Results obtained from this study showed that, although most of the samples had a high

level of Zn, Cu, K, Na, Ca, Cd, As and Mg, they were all within the acceptable limit.

However, the concentration of Pb in most samples, was found to be above the World Health

Organisation (WHO) and Kenya Bureau of Standards (KEBS) limits of 0.1 mg/kg in food

products. In Spain, Emma and Susana (2006) have determined heavy metals (Zn, Cd and

Pb) in honey by potentiometric stripping analysis. All the samples analysed presented

concentration values lower than permitted limits.

Antioxidant activities and total phenolics of different types of honey have also been studied

(Al-Mamary et al., 2002). In the studies, nine types of honey were evaluated. Yemeni

honey samples had significantly higher total phenolic content as compared to the imported

honey samples. The level of antioxidants increased with increased volume of honey

samples, and a positive correlation between percentage antioxidant and total phenolics was

observed, which increased with the higher level of samples.

The elements Al, B, Ca, Cu, Mg, Mn, Ni, and Zn were determined in nectar and honeydew

honey samples from Czech Republic. Lachman et. al., (2007) drew the conclusion that the

composition relies on both the nature and environmental contamination of the honey.


33

Blasa et al., (2006) also studied antioxidants in raw Millefiori honey. Five types of honey

were tested. Raw Millefiori honey was rich in both the amount and variety of antioxidants.

In addition, darker coloured and more crystallized honeys had stronger antioxidant activity

compared to lighter transparent honeys.

Gonzales (1999) and his colleagues also monitored color changes during storage of honeys

in relation to their composition and initial color. The outcome was that, floral origin,

polyphenolic components and deteriorative reactions all affected the stability of color of

honeys during storage. The initial colour was the parameter, which better defined the rate

of darkening in the sampled honeys.

Agaja (2014) has also used instrumental neutron activation to analyze honey samples from

Lokoja and Suleija North Central Nigeria. The concentrations of the nine elements

determined in the honey samples; Al, Br, Ca, Cl, K, Mg, Mn, Na and V, were all in

agreement with other previous workers’ result within Nigeria and in Europe.

The mineral content of Greek and German honey was investigated by Chalhoub et al.,

(2007) and Bogdanov et al., (2003) respectively, using inductively coupled plasma atomic

emission spectroscopy. They found that the variation in the concentrations of Ca, Cr, Ni,

Mg, Cu, Mn, Zn and P were similar to the values found in other recent studies and within

acceptable limits. Pb, Cd, Zn, Cu, Cr, Ni, Fe and Mn are well known as potential air or soil

contaminants of anthropogenic origin, and also found as natural ingredients of soil

minerals, indicating that honey can be used as tool for environmental, botanical and


34

geographical discriminations. In the study, variation in trace element content in different

honey types was observed to be primarily due to botanical origin rather than geographical

exposition of nectar sources.

Determination of the extent of bioaccumulation of the toxic elements: Zn, Cu, Pb , As, and

Cd in propolis and multiflower honey collected from Wroclaw area (Poland) has also been

investigated by Roman et al., (2011). Lead was found to be the most problematic element

in the honey because its average content exceeded the maximum acceptable over two fold.

Also the lead level was exceeded in 85% of the studied samples. This was attributed to the

significant contamination of soils by chemical industries and extensive urban areas.

The physical properties and chemical composition of honey from different sources have

been published by many scientists (Andrade et al., (1999); Anklam, (1998); Costa et al.,

(1999); Pe´rez-Arquillue et al., (1995); Singh and Kaur, (1997); Sporns et al., (1992);

Swallow and Low, (1990); White et al., (1975)).

Compared to other countries, there are few published research on Ghanaian honey. Some

date back to the 1990’s. Ankrah (1997) showed that Ghanaian honey samples contained

18.8% moisture, 0.8% ash, 57.0% reducing sugars calculated as invert sugar and 3.0%

sucrose sugars calculated as invert sugar and 3.0% sucrose. The results compared

favourably with those reported in the Codex Alimentarius, making the Ghanaian honey

samples acceptable for domestic and international trade. Comparative antibacterial activity

of stingless bee honey and standard antibiotics against common eye pathogens has also


35

been studied by Kwapong et al., (2013). Nevertheless, based on the available literature,

there is no information about the elemental composition of honey in Ghana.

This work focused on quantitative and qualitative analysis of the essential elements (Al,

K, Na, Ca, Mg, Fe, Cr, Co, Cu ) and heavy metals ( Hg, Pb, Cd, As) in honey samples from

Brong Ahafo, Ashanti and Greater Accra regions of Ghana using instrumental neutron

activation analysis, and atomic absorption spectroscopy to ascertain the actual

concentration of these elements.

2.9 Neutron Activation Analysis Technique

Neutron activation analysis allows for the qualitative and quantitative determination of

elements. The method is based upon the conversion of stable atomic nuclei into radioactive

nuclei by irradiation with neutrons and the subsequent measurement of the radiation

released by these radioactive nuclei (Figure 2.2). Among several types of radiation that can

be emitted, gamma radiation offers the best characteristics for the selective and

simultaneous determination of elements (IAEA TECDOC, 2001).


36

Figure 2.2: Summary of INAA procedure

By neutron activation, radionuclides may be produced from all elements present in the

sample, sometimes at very different production rates. For analysis, the resulting radioactive

sample is kept intact and the radionuclides present are determined by taking advantage of

differences in the decay rates and measuring the samples at different decay intervals,

utilizing equipment with a high energy resolution for gamma radiation. This is called non-

destructive or instrumental neutron activation analysis (INAA) (IAEA TECDOC, 2001).

An INAA procedure is characterized by;

i. activation via irradiation with reactor neutrons,

ii. measurement of the gamma radiation after one or more decay intervals,

and

iii. interpretation of the resulting gamma ray spectra in terms of the elements

present and their concentrations.


37

INAA was employed in this work because the samples do not have to undergo any chemical

treatment, prior to, nor after the activation. Because of the limited sample handling

operations, there is also a lower risk of contamination during sample preparation compared

to element analysis methods in which the sample has to be dissolved (IAEA TECDOC,

2001). Light elements such as H, C, N, O, Si which in many materials belong to the major

matrix components, do not produce radioactive products upon neutron activation. This

means that they cannot interfere with the determination of the other activities. This often

enables the observation of trace elements at detection limits in the mg/kg to µg/kg level in

matrices composed of these light elements. In addition, the high selectivity of gamma ray

spectrometry allows for simultaneous evaluation of many radionuclides. Since the signals

(Figure 2.3) in INAA are related to the properties of the atomic nucleus, the results in INAA

are not affected by the chemical and physical state of the elements. The method is well

described by physical laws and selectivity is unambiguous for all elements. The reason is

that the combination of the nuclear properties such as the decay constant (often converted

to half-life) and the energies and intensities of the gamma radiation is uniquely

characteristic for each radionuclide. This all contributes to a high degree of accuracy that

makes INAA well acknowledged for analyses related to such areas as the certification of

reference materials (IAEA TECDOC, 2001).


38

Figure 2.3: A typical Gamma-ray Spectra (Source: Hamidatou et al., 2013)

2.10 Atomic Absorption Spectroscopy Analysis Technique

An atomic absorption spectrometer is an instrument which is used to analyze the

concentrations of metals in solution. Sixty eight elements can be determined directly over

a wide range of concentrations from µg/kg to per cent levels, with good precision–typically

better than 1 % relative standard deviation. Sample preparation is generally simple and

frequently involves little more than dissolution in an appropriate acid. The instrument is

easy to tune and operate (Varian booklet, Introducing Atomic Absorption Analysis, 1997).

The basic principles of atomic absorption spectroscopy can be expressed by three simple

statements:

a) All atoms can absorb light.


39

b) The wavelength at which light is absorbed is specific for each element. If a

sample containing nickel, for example, together with elements such as lead

and copper is exposed to light at the characteristic wavelength for nickel,

then only the nickel atoms will absorb this light.

c) The amount of light absorbed at this wavelength will increase as the number

of atoms of the selected element in the light path increases, and is

proportional to the concentration of absorbing atoms.

d) The relationship between the amount of light absorbed and the

concentration of the analyte present in known standards can be used to

determine unknown concentrations by measuring the amount of light they

absorb. An atomic absorption spectrometer is simply an instrument in which

these basic principles are applied to practical quantitative analysis (Varian

booklet, Introducing Atomic Absorption Analysis, 1997).


40

CHAPTER THREE

MATERIALS AND METHODS

3.1 Honey Sample Collection Sites

Sampling was done in three regions of Ghana where honey is mostly produced; Brong

Ahafo, Ashanti and Greater Accra regions. The sampling of honey in the various regions

was carried out from August, 2014 to January, 2015. In the Brong Ahafo region, the

collection sites were Atebubu, Berekum, Drobo, Fiapre, Dumasua, Mantukwa, Nsoatre,

Kintampo, Techiman and Tanoso. In the Ashanti region, the collection sites were Jamasi,

Ntonso, Aboaso, Nkwanta, Manpongten, Fawode, Ahwiaa, Pankrono, Asenua, and Agona.

In the Greater Accra region, the collection sites were Afienya, Akweteyman, Amasaman,

Pokuase, Ablekuma, Awoshie, Oyibi, Weija, Adenta and Ayimensa (Table 3.1). To assess

the variation of metal content of the honey from the farmer to the market, the sampling was

done along the farmer-to-trader route.

Figure 3.1: Sample collection chart

(a) Honey collected from beekeepers after extraction

(before processing-BP)

(b) Honey collected from beekeepers after processing-

AP (decanting, filtration, sieving, packaging)

(c) Honey collected from retailers-RT, who

purchase directly from beekeepers


41

First batch of samples were taken directly from the beekeepers right after extraction, at the

site. Second batch of samples were taken from the beekeepers after processing (decanting,

filtering and packaging). Third batch of samples were taken from the retailers who buy

directly from the beekeepers and sell to consumers (Figure 3.1). At each sampling route,

three samples were taken. Thirty sampling sites were visited. In all, there were ninety

samples.

The samples were given respective codes that comprised acronyms of the regions, sampling

site and number, collection date and the researcher’s name. Prior to analysis, the honey

samples were stored in clean plastic bottles and tightly covered. The samples were double-

bagged and placed in hermetically closed polyethylene bags and stored at room

temperature in the dark.

Table 3.1: The sampling sites of the honey samples in the various regions

REGION SAMPLING SITES

BRONG

AHAFO

Atebubu, Berekum, Drobo, Fiapre, Dumasua, Mantukwa, Nsoatre,

Kintampo, Techiman and Tanoso

ASHANTI Jamasi, Ntonso, Aboaso, Nkwanta, Manpongten, Fawode, Ahwiaa,

Pankrono, Asenua, and Agona.

GREATER

ACCRA

Afienya, Akweteyman, Amasaman, Pokuase, Ablekuma, Awoshie,

Oyibi, Weija, Adenta and Ayimensa


42

Figure 3.2: Map of Ghana showing the sampling sites


43

3.2 Social Experiment (Questionnaire Administration)

Prior to the collection of samples, preliminary information was solicited from the

beekeepers and retailers through the administration of questionnaires. This was done in

order to have a broader view of the various extraction methods and treatment processes

employed by the farmers during honey extraction, as well as the storage conditions and

packaging materials used by the retailers. Some of the questions asked were about how

long they have been in the honey business, which people they normally sell their products

to, where the location of their apiary is, how many colonies they have, the equipment they

usually use during honey extraction, the kind of safety equipments they use. Other

questions were about the containers used for keeping or storing the products, treatment of

containers before honey storage, the source of the honey, the colour of the honey,

consistency of honey, aroma and flavor of the honey.

In addition, questions on the treatment methods used after extraction, additives added

before selling them, the type of additive added to the honey, how pest and diseases are

controlled, the chemicals employed, measures normally taken to reduce contamination of

the honey and how is it packaged before it is sold to consumers. A sample questionnaire is

at Appendix D (Table D1).

3.3 Physicochemical Analysis

3.3.1 Apparatus

Glassware

The glassware used were 30 cm stirring rod, 100 mL beakers, 10 mL and 25 mL pipette

and 50 mL pycnometer (density bottle).


44

3.3.2 Instruments

The instruments used included: pH meter (Model ECO Testr pH 2, Eutech Instrument),

Electrical Conductivity meter (Model ECO Testr 11, Eutech Instrument), Analytical

Balance with 0.001 g precision (Intell-Lab Balance, Model PM-300).

3.3.3 Experimental Procedure

Determination of pH, electrical conductivity and relative density were carried out in

triplicate for each sample.

3.3.3.1 Preparation of 10% (w/v) Honey Solution

About 1.0 g aliquot of the sample was weighed into the 100 mL beaker. This was followed

by the addition of about 10 mL of boiled deionised water (100 ºC). The mixture was then

stirred for complete dissolution of the honey samples to form a 10% (w/v) homogenized

solution. The pH and electrical conductivity of the deionised water used were 7.0 and 0

µS/cm respectively.

3.3.3.2 Determination of pH

The pH of the 10% (w/v) solution of homogenized honey prepared in boiled warm water

was then measured by a pH-meter. The pH meter was calibrated using standard buffer

solutions of pH 4.0, 7.0 and 10.0 prior to measuring the pH of the samples.

3.3.3.3 Determination of Electrical Conductivity

The conductivity of the 10% (w/v) solution of homogenized honey prepared in boiled warm

water was measured with the conductivity meter. Prior to that, the conductivity meter was

calibrated by direct comparison of EUT with conductivity meter serial number 08260033


45

using a reference electrolytic conductivity solution Lot No. 40610636025 at a temperature

of 25.42 °C and a relative humidity of 51.3 %.

3.3.3.4 Determination of Relative Density (Specific Gravity)

The relative densities of the honey samples were determined according to the procedure

below;

The empty 50 mL density bottle was weighed and filled to the brim with deionised water.

Its weight was measured again. The bottle was then filled to the brim with the honey

sample, and the weight was measured. The procedure was repeated for all the other honey

samples. The method below was then used to quantify the relative densities of the honey

samples.

RDhoney =ρhoney

ρwater

Where:

ρhoney

=Mhoney

Vhoney

ρwater

=Mwater

Vwater

But Vwater= Vhoney = 50mL

Therefore:RDhoney =Mhoney

Mwater

Where:

RDhoney = Relative Density of honey

ρhoney

= Density of honey

M honey= Mass of honey

Vhoney= Volume of honey


46

ρwater

= Density of water

Mwater= Mass of honey

Vwater= Volume of water

3.4 Determination of Heavy/Trace Metals

The heavy/trace metal contents in the honey samples were determined by two analytical

techniques; neutron activation analysis (NAA) and atomic absorption spectrometry (AAS).

3.4.1 Instrumental Neutron Activation Analysis

The following elements were determined by INAA; Cd, Cu, As, Hg, Na, Al, Mn, Ca, Mg,

K, and V.

3.4.2 Instrumentation

The Mettler Toledo XS603S digital analytical balance was used for the weighing of

samples for irradiation. Irradiation of honey samples was done in Ghana’s 30 kW miniature

neutron source reactor (MNSR), situated at the Ghana Atomic Energy Commission,

Kwabenya, Accra. Samples and the standards were irradiated at a thermal neutron flux of

5 x 1011ncm-2s-1. Samples and standards were transferred into the reactor through the

pneumatic transfer system operating at 25.0 atmospheres. Measurement of γ-irradiation

intensity of the induced radionuclides was performed on a coaxial high purity germanium

detector (HPGe) γ-ray semiconductor detector (ORTEC). The detector has an efficiency of

25% relative to the 1332.5 keV γ-line of 60Co, a resolution of 1.8 keV at 1332.5 keV γ-

lines of 60Co and a peak-to-campton ratio of 55:1.


47

The Ortec Maestro-32 γ-ray spectrum acquisition software was used for γ-ray spectrum

acquisition and quantification

3.4.3 Standard Reference Materials

Single Standard Reference Materials, NIST SRM 1643E (Estuarine sediment) from the

National Institute of Standards and Technology (USA) were used.

3.4.4 Apparatus

1.2 mL polyethylene vial, 7 mL vial, 1 mL pipette cotton wool and soldering iron rod

3.4.5 Procedure for Sample Preparation

The honey samples were homogenized in their containers to ensure uniformity before

weighing. Samples were prepared by weighing 500 mg aliquot of the sample into the 1.2

mL polyethylene vial, covered, thermally sealed with a soldering rod and labeled. The

sample-containing vials were then placed in the 7 mL vial. Cotton wool was plugged in to

make the sample firm and stable. A sample each was placed in the capsule, for the short-

lived radionuclides and for medium-lived radionuclides. NIST single standard reference

materials of concentration 10 mg/L and 20 mg/L as well as blanks, were prepared the same

way as the samples and irradiated together with the samples. Since the quantification of

concentration was based on the comparator method of neutron activation analysis, the

standards were used as comparator standards.


48

3.4.6 Irradiation of samples and standards

Before an irradiation scheme was established, preliminary studies were carried out in order

to get an accurate irradiation scheme which included the right amount of sample to

irradiate. Table 3.2 shows the irradiation schemes considered for short-lived radionuclides

before arriving at a favourable scheme (Scheme 4).

The irradiation was categorized according to the half-life of the element of interest. For

short-lived radionuclides (Al, Mg, Cu, V, Mn, Ca), samples were irradiated for two minutes

and counted for ten minutes on the detector. For medium lived radionuclides (Hg, As, Cd,

Na, K), samples were irradiated for one hour and delayed for twenty four hours followed

by ten minutes counting,

Table 3.2: Irradiation and Counting Schemes

Scheme Sample

mass (g)

Irradiation time

(min)

Delay time

(min)

Counting time (min)

1 0.5 1 5 10

2 0.5 1 0 10

3 0.5 2 5 10

4 0.5 2 0 10

3.4.7 Measurement of γ-radiation Intensity (Counting)

After irradiation, γ-radiation intensity measurement of induced radionuclide was

performed by a PC-based γ-ray spectrometry set-up. After irradiation, the γ-radiation

intensity of the short-lived radionuclides was measured immediately. For the medium-lived

radionuclides, the samples and standards were measured after 24 hour delay time to allow


49

the intensity of the radiation to decay to safe levels for human handling. The samples were

placed on the coaxial Ortec HPGe γ-ray detector connected to a multichannel analyzer

(MCA). Similarly, under the same conditions, the γ-radiation intensity of the NIST

standards irradiated together with the samples was measured at the same geometrical

distance with respect to the detector. A plexiglass source support was mounted on the

detector during the measurement in order to ensure easy and reproducible source

positioning (De Corte, 1987).

3.4.8 γ-ray Spectrum Acquisition and Quantification

Identification of γ-ray of product radionuclide was identified through the energies and

quantitative analysis of the concentration was achieved using the γ-ray spectrum analysis

software, ORTEC MEASTRO-32. Quantitative analysis was done via relative comparator

method. The peak area determinations, processing and concentration calculation were done

by Multipurpose γ-ray Spectrum Analysis 93 Software; winSPAN-2010 version 2.10.

3.4.9 Calculation of Concentration

Calculation of the concentration was done based on the relative standardization method

of NAA (Comparator Method) according to the equation:

Csamp

Cstd= (

Astd

ASamp) / (

Msamp

Mstd)

Csamp = [(Asamp

Msamp) / (

Astd

Mstd)] × Cstd


50

Where:

Csamp = Concentration of the sample

Cstd = Concentration of the standard

Asamp = Area of sample’s peak

Astd = Area of standard’s peak

Msamp = Mass of the sample

Mstd= Mass of the standard

3.4.10 Validation of the INAA Technique

To ascertain the reliability of the results, the INAA technique was validated using NIST

(USA) single standard reference materials (SRM 1643E) of concentrations 10 mg/kg and

20 mg/kg, of the various elements of interest. The results are presented in Table 4.3 (page

65).

3.5 Determination of Pb, Cr, Co and Fe Using Atomic Absorption Spectroscopy

3.5.1 Instrumentation

The Mettler Toledo XS603S digital analytical balance was used for the weighing of

samples before digestion. Digestion of samples was performed in 100 mL beakers using a

conventional Hot Plate (BIBBY-290). Atomic absorption spectrometer (VARIAN, AA 240

FS, Australia) equipped with deuterium background corrector was used for determining

the concentrations of the analytes of interest. The flame atomizer was made up of air

(oxygen) as oxidant and acetylene gas as fuel, with 13.5 Lmin-1 and 2.0 Lmin-1 flow rates

respectively.


51

3.5.2 Chemicals and Standards

65% nitric acid (HNO3) and 30% hydrogen peroxide (H2O2) were used for the digestion of

the honey samples. De-ionised water was used for all dilutions.

3.5.3 Procedure for Digestion of Samples with the Hot Plate

All digestion vessels and associated glassware were detergent washed, nitric acid

washed, and rinsed with deionized water three times prior to use. The glassware were then

dried in an oven at a temperature of 40 °C, for four hours before used (Radojevic and

Bashkin, 1999).

The samples were first prepared for determination of their metal contents by acid digestion.

The purpose was to degrade and solubilize the matrix, to release all metals for analysis, to

concentrate metals present at very low levels to bring them into a concentration range

suitable for analysis, to separate a single analyte or group of analytes from other species

that might interfere in the analysis, to dilute the matrix sufficiently so that the effect of the

matrix on the analysis will be constant and measurable and to separate different chemical

forms of the analytes for individual determination of the species present. (Patnaik, 2004).

Aggressive acid digestion usually renders all the metals into the same form and destroys

any information about the species originally present.

The samples, prior to analysis for elemental metal content were prepared by digesting the

matrix in a strong acid. Nitric acid was used, because there is no chance of forming

insoluble salts as might happen with HCl or H2SO4. Hydrogen peroxide (H2O2) was added

to increase the oxidizing power of the digestion solution. Nitric acid oxidizes the sample


52

and was therefore used before the stronger oxidizer, perchloric acid, to remove the more

readily oxidized material.

Samples were weighed directly in individually tarred digestion vessels. The honey samples

were prepared by weighing 5000 mg of each of the samples into100 mL beakers. This was

followed by the addition of 25 mL of 65% nitric acid (HNO3) and 2.5 mL of 30% (w/v)

hydrogen peroxide (H2O2). The digestion of the samples were done according to the

protocol for digestion of honey (Microwave Acid Digestion Cookbook, 1996; Jorham and

Engman, 2000).

The reaction was carried out in a fume chamber. The beakers were covered with a clean

film to reduce the evolution of poisonous gases during heating. The mixtures were then

heated on a hot plate at a temperature range of 60 – 90 ºC for 3 hours. After heating the

digestates were cooled at room temperature and quantitatively filtered under gravity using

a Whatman filter paper, diluted to 30 mL with distilled water. They were then transferred

into clean bottles, labelled appropriately and corked, for analysis with the atomic

absorption spectrometer. Using deionized water, blanks were also prepared similarly and

under the same conditions.

3.5.4 Chemical Reactions that Occurred During Digestion

The lead in the honey samples dissolved in the concentrated nitric acid, producing lead

ions and a colourless nitrogen oxide gas which oxidized to nitrogen dioxide gas (red) in

the presence of air (oxygen)


53

3Pb + 8HNO3 3Pb 2+ + 6NO3- + 2NO + 4H2O

The iron in the honey samples dissolved in the concentrated nitric acid, producing iron ions

and a colourless nitrogen oxide gas.

4Fe + HNO3 + 3H+ 4Fe3+ + NO + 2H20

3Fe + 2HNO3 + 6H+ 3Fe2+ + 2NO + 4H20

The chromium in the honey samples dissolved in the concentrated nitric acid, producing

chromium ions and a colourless nitrogen oxide gas which oxidizes to nitrogen dioxide gas

(red) in the presence of oxygen.

Cr + 4HNO3 Cr 3+ + 3NO3- + NO + 2H2O

The cobalt in the honey samples dissolved in the concentrated nitric acid, accompanied by

the formation of cobalt ions and a colourless nitrogen oxide.

3Co + 2HNO3 + 6H+ 3Co 3+ + 2NO + 4H2O

3.5.5 Calibration of Atomic Absorption Spectrophotometer

The commercially available standard stock solutions used for the calibration were: 1000±4

mgPbL-1 in 2% (w/w) HNO3; 1000±4 mgCrL-1 in 2% (w/w) HNO3; 1000±4 mgFeL-1 in

2% (w/w) HNO3; 1000±4 mgCoL-1 in 2% (w/w). Standards of known concentrations for

the various elements of interest were prepared from the commercial stock standard

solutions and used for the calibration of the atomic absorption spectrometer.


54

The absorbances measured for the various standard solutions were used to prepare a linear

regression line and the concentration of each element was deduced from their respective

lines as shown in Figures A1–A4 (Appendix A). The equations compared absorbance with

concentration. It therefore enabled quantitative analysis to be carried out. Three blanks

solutions were prepared in a similar way as that of the sample. The sample solutions were

corrected for absorbances before actual calculations were done. The calibration solution

data obtained for Pb, Cr, Co and Fe are presented in Table 3.3.

Table 3.3: Standards Prepared for the Calibration of the AAS

Analyte Concentration of the Calibration Standard (mg/L)

Calibrant 1 Calibrant 2 Calibrant 3

Pb 2.00 5.00 10.00

Cr 1.00 2.00 5.00

Co 1.00 2.00 5.00

Fe 2.00 5.00 10.00

3.5.6 Determination of Concentration of Honey Sample

The instrumental parameters for the AAS are presented in Table 3.4.


55

Table 3.4: Flame AAS Instrument parameter for Pb, Fe, Cr, Co Analysis

Instrument

parameter

Analyte

Pb Cr Co Fe

Wavelength (nm) 217.0 357.9 240.7 248.3

Slit with (nm) 1.0 0.2 0.2 0.2

Lamp current (mA) 5.0 7.0 7.0 7.0

Air flow (L/min) 13.5 13.5 13.5 13.5

The absorbances of the digested honey samples were determined after the calibration of

the instrument. The concentrations of the elements of interest were deduced from their

respective regression lines, and the actual concentrations were then calculated.

3.5.7 Calculation of Concentration

The equation below was used to calculate the actual concentrations of the elements

Csamp_actual =Csamp_calib × Df × Vn

Msamp

Where;

Csamp_actual= Actual concentration of sample

Csamp_calib= Sample concentration (Calibration curve)

Df = Dilution Factor

Vn=Norminal Volume

Msamp=Mass of Sample


56

Table 3.5: Detection Limit of Elements Determined by AAS

ELEMENT DETECTION LIMIT (mg/L)

Pb 0.040

Fe 0.240

Cr 0.006

Co 0.005

3.6 DATA ANALYSIS

Data organization and graphical plots of results was done with Microsoft Excel version

2010. One way ANOVA (analysis of variance) was performed using IBM SPSS Statistics

Version 20. ANOVA was used to test and determine whether there were significance

differences in the concentration of the samples as it passes through the various processes

or whether at least one of the groups tested differs from the other groups. However, the

ANOVA cannot tell from the test which group differs.

Least Significant Difference (LSD) and Tukey test were therefore done to determine which

process significantly affects the honey’s composition. The LSD calculates the smallest

significant between means as if a test had been run on those means (as opposed to all of

the groups together). This enables direct comparisons between two means from two

individual groups to be made. Any difference larger than the LSD is considered a

significant result (Fisher, 1935).

The formula for the least significant difference is:

LSDA,B = t0.05/2DFw√MSw(1nA

⁄ + 1nB

⁄ )


57

Where:

t = Critical value from a t-distribution table

n = Number of scores used to calculate the means

MSw = Mean Square within, obtained from the results of the ANOVA test

DFw = Degrees of Freedom

The Tukey method, is a single-step multiple comparison procedure and statistical test also

used to find means that are significantly different from each other. It is based on a formula

very similar to that of the t-test. Tukey's test is essentially a t-test, except that it corrects for

experiment-wise error rate (when there are multiple comparisons being made, the

probability of making a type I error increases -Tukey's test corrects for that, and is thus

more suitable for multiple comparisons than doing a number of t-tests would be) (Tukey,

1949; Linton et al., 2007).

The formula for Tukey's test is:

qs =YA−YB

SE,

Where;

YA = the larger of the two means being compared,

YB = the smaller of the two means being compared, and

SE= the standard error of the data in question.

This ‘qs’ value can then be compared to a ‘q’ value from the studentized range distribution.

If the ‘qs’ value is larger than the ‘qcritical’ value obtained from the distribution, the two

means are said to be significantly different (Linton et al., 2007).


http://www.statisticshowto.com/tables/t-distribution-table/

https://en.wikipedia.org/wiki/Multiple_comparison

https://en.wikipedia.org/wiki/Statistical_test

https://en.wikipedia.org/wiki/Multiple_comparisons

https://en.wikipedia.org/wiki/Type_I_error

https://en.wikipedia.org/wiki/Standard_error_(statistics)

58

CHAPTER FOUR

4.0 RESULTS AND DISCUSSION

4.1 Response From Administered Questionnaires

Results of the responses given by the beekeepers and the retailers are results summarized

in Table D2 (Appendix D).

The social experiment revealed that, some of the apiaries were closer to industries (6.7%),

tarred roads and filling stations (26.6%), while some (23.3%) were far away from human

Settlement. (Figure 4.1).

Figure 4.1: Response to questions about the location of apiaries

With regard to the equipment used in the extraction, some of the farmers use wood (43.3%),

metal (10%) and both wood and metals (46.7%) (Table D2, Appendix D). On measures

taken to reduce contamination, only 56.7% of them admitted to using both gloves and head

covers while others use either one of them or none at all due to their availability. It was

observed that, the processes usually used in extracting the honey out of the combs were

decanting, filtering, sieving with nets, heating to melt, solar extraction, cold extraction and

6.70%

26.70%

23.30%

13.30%

Location of Apiaries

Close to Industries (About 10 m)

Close to Tarred Road/ Filling

Station (About 10 m)

Few Meters Away From Human

Settlement

Others


59

hand-squeezing. On additives, a few of them (13.3%) admitted that they add a little water

to either increase the volume or improve the honey’s consistency (Figure 4.2). Majority of

the respondents (86.7%) however said they add no additives.

Figure 4.2: Response to questions about addition of additives

For containers used in storing the honey, 20% and 60% of the beekeepers used metal and

plastic containers respectively. The use of fresh or new packaging materials was very rare

when compared to the use of recycled materials (Figure 4.3), such as used beer and soft

drink bottles, calabashes, used plastic mineral water bottles and plastic cooking oil gallons,

because they are cheap and affordable. As to how the containers are treated before use,

some of them said they rinse with warm water, others wash with detergents whiles a few

of them (13.3%), use them without washing or rinsing. Some of the retailers sell them at

the roadsides, hawking from one place to another or at the markets.

13.30%

86.70%

Addition of Additives

Yes

No


60

Figure 4.3: Response to questions about packaging materials used for storing honey

4.2 Physicochemical Studies

Results for physicochemical parameters (pH, electrical conductivity, and specific gravity)

are summarized in Table 4.1.

4.2.1 pH of Honey

All the honey samples analyzed were found to be acidic. The acidity of honey may be due

to the presence of organic acids, particularly gluconic acid and inorganic ions such as

phosphate and chloride (Nandaa et al., 2003). Generally, in the Brong Ahafo region, pH

ranged from 3.8 (Kintampo) to 6.0 (Tanoso) (Table 4.1). For Ashanti, pH varies from 4.8

(Asenua) to 6.1 (Manpongten). The pH of honey from the Greater Accra region varied from

3.6 (Weija) to 6.1 (Ablekuma). The measured pH values agree with the limits set by the

25.00%

56.00%

19.00%

Containers for Keeping or Packaging Honey

New Plastics Containers

Used or Recycled Plastic

Containers

Metal or Glass Containers


61

National Honey Board of United States (3.4 to 6.1) and also compares favourably with the

pH of honey from other parts of the world (Table 4.2).


62

Table 4.1: The pH, Electrical Conductivity, and Specific Gravity

Regions Towns Physicochemical Parameters

pH Electrical Conductivity (µS/cm) Specific Gravity

Brong Ahafo Atebubu 5.3 ± 0.2 16.7 ± 0.3 1.399 ± 0.001

Fiapre 5.5 ± 0.1 44.4 ± 0.7 1.443 ± 0.002

Drobo 5.9 ± 0.2 17.2 ± 0.4 1.415 ± 0.002

Dumasua 5.6 ± 0.1 25.9 ± 0.3 1.418 ± 0.001

Mantukwa 5.5 ± 0.1 14.3 ± 0.1 2.031 ± 0.006

Nsoatre 5.6 ± 0.3 22.4 ± 0.2 1.563 ±0.002

Kintampo 3.8 ± 0.2 12.0 ± 0.5 1.425 ± 0.005

Techiman 5.3 ± 0.1 11.9 ± 0.3 1.368 ± 0.004

Tanoso 6.0 ± 0.2 31.8 ± 0.4 1.644 ± 0.003

Berekum 5.9 ± 0.3 12.7 ± 0.1 1.426 ± 0.001

Ashanti Ntonso 5.7 ± 0.3 18.3 ± 0.1 2.016 ± 0.005

Jamasi 5.9 ± 0.2 12.5 ± 0.2 1.875 ± 0.004

Aboaso 5.6 ± 0.1 16.0 ± 0.6 1.900 ± 0.004

Manpongten 6.1 ± 0.2 12.7 ± 0.2 1.430 ± 0.002

Nkwanta 5.5 ± 0.1 41.6 ± 0.5 1.424± 0.002

Fawode 5.5 ± 0.1 13.0 ± 0.2 1.297 ± 0.005

Ahwiaa 5.2 ± .02 34.1 ± 0.2 1.423 ± 0.007

Agona 5.6 ± 0..3 15.2 ± 0.4 1.616± 0.002

Pankrono 6.0 ± 0.2 12.3 ± 0.5 1.429 ± 0.005

Asenua 4.8 ± 0.3 14.8 ± 0.3 1.422 ± 0.003

Greater Accra Ayimensa 6.0 ± 0.6 13.2 ± 0.2 1.419 ± 0.003

Akweteyman 4.9 ± 0.5 32.4 ± 0.5 1.538± 0.003

Amasaman 6.0 ± 0.4 13.7 ± 0.4 1.525± 0.005

Pokuase 3.7 ± 0.3 23.3 ± 0.4 1.642 ± 0.004

Awoshie 5.9 ± 0.2 12.4 ± 0.2 1.433 ± 0.001

Weija 3.6 ± 0.2 12.8 ± 0.2 1.409 ± 0.003

Adenta 4.5 ± 0.3 22.5 ± 0.2 1.426 ± 0.003

Ablekuma 6.1 ± 0.3 21.5 ± 0.3 2.001± 0.002

Oyibi 5.5 ± 0.4 34.6 ± 0.3 1.404 ± 0.002

Afienya 5.3 ± 0.3 14.0 ± 0.1 1.412 ± 0.004


63

The pH values of honey are of great significance during extraction, processing and storage

as they influence texture, stability and shelf-life (Baroni et al., 2009). The acidic nature of

the honey is important because it inhibits the presence and growth of microorganisms

(Gomes et al., 2010).

Table 4.2: Comparison of pH of Ghanaian honey with that from other parts of the

world

Country pH Range Reference

Ghana 3.60-6.10 This study

Algeria 3.49-4.53 Ouchemoukh et al., (2007)

Brazil 3.10-4.05 Saxena et al., (2010)

Spain 3.63-5.01 Saxena et al., (2010)

Ethiopia 3.82-4.45 Kebede et al., (2012)

India 3.70-4.70 Saxena et al., (2010)

Turkey 3.67-4.57 Saxena et al., (2010)

Portugal 3.70-4.30 Gomes et al., (2010)

4.2.2 The Electrical Conductivity of Honey

Electrical conductivity of honey from the three Regions varied with sampling sites. The

electrical conductivity values recorded ranges from 11.9 µS/cm (Techiman) to 44.4 µS/cm

(Fiapre) in the Brong Ahafo region (Table 4.1). For Ashanti, electrical conductivity varies

from 12.3µS/cm (Pankrono) to 41.6 µS/cm (Nkwanta). The electrical conductivity of

honey from the Greater Accra region varied from 12.4 µS/cm (Awoshie) to 34.6 µS/cm

(Oyibi). These values agree with the limits set by Ghana Standards Authority, Codex

Alimentarius and Council of European Union (CODEX, 2001). The electrical conductivity

depends on the contents of ash, inorganic acids, proteins, some complex sugars and polyols

content in addition to the mineral content which varies with botanical origin (Singh and

Bath, 1997).


64

4.2.3 The Specific Gravity of Honey

The specific gravity of honey is measure of the density of honey relative to water. The

Specific gravity of the honey samples analysed ranged from 1.297 to 2.031, implying that

they were all heavier than water (Table 4.1). They were higher than the values (1.2081 to

1.2270) reported in Libyan honey (Mohamed et al., 2013). These variations in the specific

gravity may be related to the water content and differences in the chemical composition of

the honey (Singh et al., 1997). Although the Ghana Standards Authority has not yet set the

allowable limits, the Food and Agricultural Organisation (2007) mentions the average

specific gravity of honey to be approximately 1.44. Most of the honey samples analysed

had specific gravity levels closer to this value.

4.3 Results of Elemental Concentration Determination

4.3.1 Validation of INAA Results

The quantitative method of the INAA analytical Technique was validated using NIST

(USA) single Standard Reference Materials (SRM 1643E) of concentrations 10 mg/L and

20 mg/L, of the various elements of interest. The results obtained from the analysis are

shown in Tables 4.3. The values obtained were in good agreement with the certified values.

The measured concentration values showed a deviation below 10% from the certified

values. The INAA quantitative method was therefore validated for the results for Ca, K,

Na, Al, Mg, Mn, V, Cu, As, Hg, and Cd in the samples which were determined by the

method.


65

Table 4.3: Comparison of Measured and Prepared Standards - Results of 10 mg/L and 20 mg/L Single Standard Elements

used for the Validation

Element Concentration(mg/L)

Measured Prepared Recovery (%) Measured Prepared Recovery (%)

Ca 9.51 ± 0.03 10.00 95.10 19.03 ± 0.04 20.00 95.15

K 9.88 ± 0.04 10.00 98.80 19.73 ± 0.02 20.00 98.65

Na 10.24 ± 0.02 10.00 102.40 20.47 ± 0.03 20.00 102.35

Al 9.80 ± 0.03 10.00 98.00 19.60 ± 0.02 20.00 98.00

Mg 9.37 ± 0.02 10.00 93.70 18.84 ± 0.01 20.00 94.20

Mn 9.93 ± 0.04 10.00 99.30 19.82 ± 0.04 20.00 99.10

V 9.76 ± 0.06 10.00 97.60 19.66 ± 0.06 20.00 98.30

Cu 10.06 ± 0.04 10.00 100.60 20.04 ± 0.03 20.00 100.20

As 9.94 ± 0.06 10.00 99.40 19.91 ± 0.07 20.00 99.55

Hg 10.16 ± 0.04 10.00 101.60 20.38 ± 0.04 20.00 101.90

Cd 9.81 ± 0.05 10.00 98.10 19.68 ± 0.05 20.00 98.40


66

4.3.2 Elemental Content of Honey from the Three Regions of Ghana

Results obtained from the analysis were reported in mg/kg since permitted levels of most

elemental concentrations are declared in mg/kg by various organizations. However,

because the concentration values obtained for Ca and K were very high, they were

converted to g/kg using the formula below:

Elemental concentration (g/kg) = Calculated concentration (mg/kg)

1000

The elemental content in honey from the selected sampling areas in the various regions is

presented in Table B1 (Appendix B). The results of the mean concentrations and the

standard deviations obtained as the honey samples move through the various processes are

presented in Tables 4.4 – 4.6. The elemental levels were also monitored from one sampling

site to another. The concentrations of most of the elements in the honey were significantly

different from each other depending on the sampling area. An example is shown (Figure

4.4) for Pb concentration in honey from selected sampling areas.


67

Figure 4.4: Variation of Pb concentrations in honey from selected sampling sites

The elemental levels were also monitored as the samples passed through various processes

or stages, thus before processing by the farmers (BP), after processing (filtering, sieving,

heating, decanting, squeezing), and from the retailers (RT).

Hg, Cd, and As were all below detection limit (Table B1-B3, Appendix B). Generally, the

elemental concentration were of the order; K > Ca > Na > Mn > Al > Mg > Cu > V > Fe

> Pb > Co > Cr.

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Co

nce

ntr

atio

n o

f P

b (

mg/k

g)

Sampling Sites

Variation of Pb in all the BP samples


68

Table 4.4: Mean Elemental Composition of Honey from Brong Ahafo

*-concentration in g/kg

BRONG AHAFO REGION

Element

(mg/kg)

Atebubu Fiapre Drobo Dumasua Mantukwa Nsoatre Kintampo Techiman Tanoso Berekum

Co Mean 0.0357 0.0363 0.0400 0.0370 0.0260 0.0340 0.0530 0.0297 0.0113 0.0300

S.D 0.0006 0.0006 0.0000 0.0050 0.0000 0.0017 0.0286 0.0065 0.0021 0.0052

Pb Mean 0.2180 0.6200 0.4840 0.4800 0.3280 0.2620 0.4700 0.4200 0.6220 0.5300

S.D 0.1148 0.0615 0.0682 0.0591 0.1397 0.0781 0.1741 0.1041 0.0500 0.1123

Cr Mean 0.0467 0.0450 0.0870 0.1686 0.0413 0.0383 0.2973 0.0367 0.0367 0.0433

S.D 0.0058 0.0017 0.0728 0.2203 0.0050 0.0068 0.2177 0.0100 0.0100 0.0230

Fe Mean 3.9080 4.9880 3.1800 5.8920 3.4820 3.9200 3.2420 4.6100 2.6900 3.3800

S.D 0.4022 1.5968 0.5495 0.3986 0.4128 0.3779 0.1570 0.6144 0.1693 0.2631

Mg Mean 542.4640 541.0550 395.6321 339.7967 430.4143 405.3100 308.4627 383.6543 385.7790 383.2133

S.D 2.5729 9.8081 4.5614 3.2242 5.9471 3.6732 6.1896 3.8094 4.0316 17.0224

V Mean 33.2817 29.9560 20.7887 21.1967 8.9260 25.4073 30.8617 17.588 31.2320 20.3197

S.D 2.6276 7.5348 4.8927 1.1115 1.0122 3.2800 1.1258 0.3230 1.6231 4.2643

Cu Mean 197.7827 20.2270 13.2587 6.8350 22.6147 86.3010 9.6827 106.7940 101.6483 81.5510

S.D 4.7480 2.6033 2.6119 1.4735 3.0496 1.5987 7.9975 1.1547 0.2689 7.0331

Al Mean 1174.5233 247.0793 439.2717 484.5793 194.6703 179.3197 591.014 445.3960 312.4480 205.1417

S.D 11.6759 14.0442 26.0707 4.2408 5.8756 6.0833 45.5349 1.7131 3.0821 12.3834

Ca* Mean 247.1807 197.3467 176.6833 171.9433 63.3110 59.7103 177.4467 151.9367 91.9300 141.4300

S.D 32.4599 28.3855 8.6574 17.3000 4.4043 26.4403 15.2994 0.1201 1.6956 53.5398

Mn Mean 1822.7750 1653.4533 3467.5883 1843.3847 1356.5773 1455.2943 1993.5473 2139.2213 1506.6863 2004.1577

S.D 12.6003 44.5709 7.1601 147.9600 25.8739 42.0040 3.0223 32.4124 6.6413 4.3472

K* Mean 282.4567 294.6753 1453.4310 475.1277 187.5967 562.2890 112.9793 341.1573 425.2020 1101.5650

S.D 1.0987 0.1986 0.0301 0.1498 4.3146 3.7203 0.0510 1.0164 0.7097 0.0044

Na Mean 4657.3620 4737.7720 5880.6033 3946.8863 4845.2267 4210.4463 3777.6533 3810.0236 3000.3900 4775.4903

S.D 39.1503 10.6335 51.4924 4.2662 49.3571 96.6931 57.2630 14.0179 9.4550 22.2575


69

Table 4.5: Mean Elemental Composition of Honey from Ashanti region


ASHANTI REGION

Element

(mg/kg)

Ntonso Jamasi Aboaso Mampong-

ten

Nkwanta Fawode Ahwiaa Agona Pankrono Asenua

Co Mean 0.0130 0.0267 0.0327 0.0347 0.0650 0.0370 0.0663 0.0307 0.0253 0.0620

S.D 0.0000 0.0114 0.0058 0.0040 0.0017 0.0231 0.0552 0.0050 0.0107 0.0236

Pb Mean 0.7100 0.5080 0.1520 0.3800 0.3640 0.5160 0.5400 0.3360 0.22240 0.3000

S.D 0.1057 0.0250 0.0577 0.1006 0.0330 0.1041 0.0540 0.1917 0.1026 0.0908

Cr Mean 0.0317 0.0349 0.0343 0.2173 0.0477 0.0457 0.0423 0.0500 0.0290 0.0277

S.D 0.0188 0.0252 0.0023 0.1415 0.0006 0.0072 0.0023 0.0035 0.0072 0.0116

Fe Mean 1.9500 4.4620 4.1560 3.3180 1.7300 3.3980 2.2200 2.9980 3.2000 4.4620

S.D 0.4987 0.3064 0.0976 1.0716 0.1337 0.3412 0.1324 0.1142 0.1752 0.1230

Mg Mean 418.6156 330.2323 100.0001 195.1350 318.9280 211.6340 440.6633 514.9543 671.544 157.2753

S.D 25.0464 10.3771 3.004 3.5554 12.4204 6.7312 9.9946 5.1355 11.2443 3.6585

V Mean 4.9856 11.9867 6.1073 15.6793 10.8983 5.1563 9.2680 0.5037 5.7290 3.8473

S.D 1.7740 3.7009 0.0821 3.1704 2.0811 2.7058 2.7125 0.0172 1.3822 1.1709

Cu Mean 15.0090 190.3077 84.3117 8.2970 74.9140 53.8947 24.1037 15.2230 10.4060 107.5417

S.D 1.6881 3.3890 3.6199 3.0369 2.2600 4.1751 0.0879 3.5117 1.0351 4.7473

Al Mean 279.6383 251.4637 317.3800 229.2820 303.1423 282.8387 252.842 249.3027 530.6137 244.5623

S.D 19.2713 4.1989 0.7625 6.3122 6.9782 2.5205 13.5076 24.1836 39.6420 2.5200

Ca* Mean 72.6733 190.9293 121.8033 120.2153 67.1590 102.2143 58.4980 47.9207 146.2220 74.8833

S.D 2.3255 69.8371 1.3162 3.4519 4.2855 19.2318 0.6632 12.7023 32.5773 4.2997

Mn Mean 3137.7000 1069.6100 1725.8800 1163.9900 1404.2400 1550.1600 2842.6400 2534.0800 3477.4300 1940.5600

S.D 72.8965 54.2460 6.9726 50.9762 54.5700 45.6547 40.5790 38.1607 2020.6138 17.9672

K* Mean 260.4087 364.6210 588.2210 1703.0633 146.7010 963.6800 461.2683 1271.8577 585.8680 855.2023

S.D 1.4527 0.0772 1.8282 58.6373 0.0598 0.4073 0.1712 0.2666 0.1184 0.7521

Na Mean 5529.5887 6176.7757 5113.9673 4858.9260 8254.2360 6927.9407 4073.4293 5845.7257 5777.8963 4426.3760

S.D 27.4145 10.8066 5.9912 51.9602 300.4345 30.1026 10.0650 55.6901 63.1348 11.2527


70

Table 4.6: Mean Elemental Composition of Honey from Greater Accra

GREATER ACCRA REGION

Element

(mg/kg)

Ayime-

nsa

Akwetey-

man

Amasam-

an

Pokuase Awoshie Weija Adenta Ablekuma Oyibi Afienya

Co Mean 0.0380 0.0380 0.0473 0.0363 0.0193 0.0360 0.0420 0.0360 0.0410 0.0637

S.D 0.0017 0.0026 0.0023 0.0023 0.0021 0.0000 0.0000 0.0000 0.0000 0.0287

Pb Mean 0.3500 0.2960 0.3680 0.4840 0.1960 0.3560 0.4700 0.1500 0.2320 0.1740

S.D 0.1805 0.1762 0.1712 0.1638 0.1265 0.1941 0.1350 0.0360 0.2446 0.1277

Cr Mean 0.0413 0.0373 0.0410 0.0503 0.0447 0.0493 0.0407 0.0420 0.0460 0.0610

S.D 0.0012 0.0012 0.0017 0.0067 0.0072 0.0025 0.0050 0.0000 0.0035 0.0154

Fe Mean 2.7800 2.7300 5.6480 2.7940 3.0820 2.9000 3.3700 3.0420 4.2500 4.6680

S.D 0.9176 0.6663 4.6878 0.2863 0.7404 0.2806 1.0367 0.4315 0.2793 2.5214

Mg Mean 92.5180 311.8213 228.6547 329.9510 81.9697 128.8803 196.0753 146.7843 80.1720 242.8413

S.D 0.5432 10.2334 2.1899 17.8537 6.3757 5.6825 18.6497 2.9045 3.9183 4.1836

V Mean 1.2193 6.8247 912.7723 3.1043 1.4440 5.7353 5.2080 7.1883 1.7227 4.4370

S.D 0.2127 1.2389 3.9491 0.0679 0.2690 1.3934 0.8032 4.3207 1.2959 4.1395

Cu Mean 152.2703 30.9353 254.6657 5.5353 27.3097 80.1523 274.6233 67.9913 16.2833 61.7223

S.D 3.4260 0.8467 5.5395 1.1862 7.7304 3.5696 12.3676 4.1289 5.6608 5.7159

Al Mean 227.1263 509.3520 254.9110 379.2083 64.6103 196.1067 86.6410 77.0860 105.5190 102.4607

S.D 20.8868 12.0049 39.2325 10.7243 3.8583 3.0030 2.6875 1.3155 6.2140 4.7072

Ca* Mean 45.6503 75.2987 73.8903 109.8590 56.0767 62.8880 25.2557 155.1310 238.0643 58.1713

S.D 5.1620 1.5653 0.3067 1.2384 5.3052 0.6315 1.4881 2.2202 7.0471 0.5684

Mn Mean 2540.1500 839.1570 2261.5600 2495.0400 1297.6400 970.1210 1164.3700 1382.5000 906.4910 1372.5000

S.D 26.3693 55.1474 31.2977 15.1567 5.5976 6.1121 36.7713 60.9132 0.6716 17.9205

K* Mean 317.4070 430.0830 181.5580 323.5480 167.0830 332.4610 681.5480 456.2200 231.1830 408.6290

S.D 0.1238 0.0404 0.0418 0.1554 0.1007 1.2107 0.1695 0.0494 0.0751 0.0442

Na Mean 5727.2407 4196.0680 3307.8437 912.5870 1269.1213 1980.7493 4693.3287 2582.4847 3157.1637 4215.1917

S.D 49.4495 9.3945 46.2541 13.1610 7.4207 9.7254 28.1226 6.2825 5.0700 4.7223



71


71

4.3.3 Elemental Concentrations of Honey from Brong Ahafo Region

The concentration observed in the region were K (112.933-1453.454 g/kg); Ca (62.135 –

283.690 g/kg); Na (2993.418-5919.315 mg/kg); Mn (1339.216-3474.237 mg/kg); Al

(175.369-1186.369 mg/kg); Mg (302.015 – 545.336 mg/kg); Cu (4.991-203.265 mg/kg),

V (8.032-35.021mg/kg); Fe (2.496-6.792 mg/kg); Pb (0.096-0.678 mg/kg); Cr (0.026-

0.423 mg/kg) and Co (0.009-0.086 mg/kg).

With the exception of Al (in the Berekum samples) where there was a decrease in

concentration, all the other elements increased in concentration along the supply chain

(before processing, after processing, and from the retailer) (Figures 4.5 to 4.16).

To monitor which of the subsequent handling processes significantly affects the honey’s

composition, the data were subjected to Analysis of Variance (ANOVA) at 95% confidence

interval. With the exception Co (with P>0.05, Table C1, Appendix C), the samples taken

from Atebubu showed statistically significant differences in concentrations of all the other

elements (K, Ca, Na, Mn, Al, Mg, Cu, V, Fe, Cr, Pb) at 95% confidence interval (P<0.05,

ANOVA). They were therefore subjected to Least Significant Difference and Tukey

analysis to determine where the differences arose from. The analysis revealed that, for Cr

and K, the BP values were far less than the mean concentration (Table 4.4), but the AP and

RT values were closer to the mean, implying that the changes in composition of these

elements can be attributed to how the farmer treated the honey, after extraction. The other

elements however, all had their before processing, after processing and retailer values

significantly deviating from their respective mean concentrations (Table 4.4). Similar trend

was observed in the results of the samples taken from Dumasua, Mantukwa, and Techiman.


72

Figure 4.5: Concentration of Co in all the samples analysed

-0.05

0

0.05

0.1

0.15

0.2C

once

ntr

atio

n o

f C

o (m

g/k

g)

Sampling Site

Concentration of Co in all the samples

Before Proc. After Proc. Retailer


73

Figure 4.6: Concentration of Pb in all the samples analysed

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Conce

ntr

atio

n o

f P

b (

mg/k

g)

Sampling Sites

Concentration of Pb in all the samples

Before Proc. After Proc Retailer


74

With the exception of Co and Cr in the samples taken from Fiapre, (with P>0.05, ANOVA),

the differences in concentration of all the other elements (K, Ca, Na, Mn, Al, Mg, Cu, V,

Fe, Pb) were statistically significant at 95% confidence interval (P<0.05, ANOVA). The

LSD and Tukey analysis revealed that, for K, the RT value deviated significantly from the

mean, but the BP and AP values were closer to the mean, implying that the changes in

composition of these elements can be attributed to how the Retailer treated the honey, after

buying it from the farmer. The other elements however, all had their BP, AP and RT values

significantly deviating from their respective mean concentrations. Similar trend was

observed in the results from Drobo, Nsoatre and Berekum.

The statistical analysis of results from Kintampo and Techiman were similar. The

differences in concentration of all the elements were statistically significant at 95%

confidence interval (P<0.05, ANOVA). However, the LSD and Tukey analysis revealed

that, in the results of Kintampo, for Cr and K, the BP values were far less than the mean,

but the AP and RT values were closer to the mean, implying that the changes in

composition of these elements can be attributed to how the farmer treated the honey after

extraction. In the results of Tanoso, for V and K, the LSD and Tukey analysis revealed

that, in both metals the RT value deviated significantly from the mean, but the BP and AP

values were closer to the mean, signifying that the changes in composition of these

elements can be attributed to how the Retailer handled the honey, after buying it from the

farmer. The other elements however, all had BP, AP and RT values significantly deviating

from their respective mean concentrations.

The null hypothesis (that the subsequent handling processes honey goes through after

harvesting has no significant effect on its composition) was therefore rejected.


75

Figure 4.7: Concentration of Cr in all the samples

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Conce

ntr

atio

n o

f C

r (m

g/k

g)

Sampling Sites

Concentration of all Cr in the samples



76

Figure 4.8: Concentration of Fe in all the samples analysed

-4.000

-2.000

0.000

2.000

4.000

6.000

8.000

10.000

12.000

14.000

16.000

18.000

Conce

ntr

atio

n o

f F

e (m

g/k

g)

Sampling Site

Concentration of Fe in all the samples

Before Proc. After Proc Retailer


77

4.3.4 Elemental Concentrations of Honey from Ashanti Region

The highest concentration was observed for K (146.666-1770.770 g/kg); Ca (39.917 –

271.566 g/kg); Na (4062.321-8277.351 mg/kg); Mn (1009.020-3501.004 mg/kg); Al

(223.687-576.354 mg/kg); Mg (97.369 – 681.236 mg/kg); Cu (5.186-192.666 mg/kg); V

(0.490-19.268 mg/kg); Fe (1.548-4.812 mg/kg); Pb (0.090-0.828 mg/kg); Cr( 0.010-0.378

mg/kg) and Co (0.013-0.130 mg/kg) in that order.

With the exception of Cu (in the samples collected at Agona and Ntonso) and Ca (in the

Manpongten samples), where there was a decrease in concentration, all the elements in the

samples increased in concentration as they moved through the various stages or processes

(before processing, after processing, and from the retailer) (Figures 4.5 to 4.16).

To monitor which of the subsequent handling processes significantly affects the honey’s

composition, the data were subjected to Analysis of Variance (ANOVA) at 95% confidence

interval.

With the exception Co and Pb (with P > 0.05, ANOVA), the samples taken from Ntonso

showed statistically significant differences in concentrations of all the other elements (K,

Ca, Na, Mn, Al, Mg, Cu, V, Fe, Cr) at 95% confidence interval (P<0.05, ANOVA). They

were therefore subjected to LSD and Tukey analysis to determine where the differences

arose from. The analysis revealed that, for Cr the BP values were far less than the mean,

but the AP and RT values were closer to the mean concentration (Table 4.5). This implies

that the changes in composition of these elements can be attributed to how the farmer

treated the commodity after extraction. The other elements however, all had their BP, AP


78

and RT values significantly deviating from their respective mean concentrations (Table

4.5), implying that the variations in composition of these elements can be attributed to both

the farmer and the retailers, with regard to how they treated and stored the honey samples.

With the exception Cr and K (with P>0.05), the samples taken from Jamasi showed

statistically significant differences in concentrations of all the other elements (Ca, Na, Mn,

Al, Mg, Cu, V, Fe, Pb) at 95% confidence interval (P<0.05, ANOVA). The LSD and Tukey

analysis revealed that, in Co and Pb, BP values were far less than the mean, but the AP and

RT values were closer to the mean, implying that the changes in composition of these

elements can be attributed to how the farmer treated the honey after extraction. The other

elements however, all had their BP, AP and RT values significantly deviating from their

respective mean concentrations.

The statistical analysis results of samples from Aboaso and Manpongten samples were

similar. With the exception Co and Cr (with P>0.05, ANOVA) the differences in

concentration of all the elements were statistically significant at 95% confidence interval

(P<0.05, Table C2: Appendix C). LSD and Tukey analysis revealed that, the other

elements however, all had their BP, AP and RT values significantly deviating from their

respective mean concentrations, implying that the variations in composition of these

elements can be attributed to both the farmer and the retailers with regard to how they

treated and stored the honey samples.


79

Figure 4.9: Concentration of Mg in all the samples analysed

0

100

200

300

400

500

600

700

800

Conce

ntr

atio

n o

f M

g (

mg/k

g)

Sampling Site

Concentration of Mg in all the samples



80

Figure 4.10: Concentration of V in all the samples analysed

-5

0

5

10

15

20

25

30

35

40

45C

once

ntr

atio

n o

f V

(m

g/k

g)

Sampling Sites

Concentration of V in all the samples



81

Figure 4.11: Concentration of Cu in all the samples analysed

-50

0

50

100

150

200

250C

once

ntr

atio

n o

f C

u (

mg/k

g)

Sampling Sites

Concentration of Cu in all the samples



82

Figure 4.12: Concentration of Al in all the samples analysed

-5

0

5

10

15

20

25

30

35

40

45

Conce

ntr

atio

n o

f A

l (

mg/k

g)

Sampling Sites

Concentration of Al in all the samples



83

The statistical analysis results of the samples from Agona and Asenua samples were also

similar. With the exception Co (with P>0.05) the differences in concentration of all the

elements were statistically significant at 95% confidence interval (P<0.05, ANOVA). The

LSD and Tukey analysis revealed that, for Cr ( in both of them), the RT values were far

more than the mean, but the BP and AP values were closer to the mean (Table 4.6),

signifying that the changes in composition of these elements can be attributed to how the

retailer treated the honey, after buying it from the farmer.

At Fawode, with the exception Co and V (with P>0.05) the differences in concentration of

all the elements were statistically significant at 95% confidence interval (P<0.05,

ANOVA). For K, the LSD and Tukey analysis revealed that, BP values were far less than

the mean, but the AP and RT values were closer to the mean (Table 4.5), implying that the

changes in composition of these elements can be attributed to how the farmer treated the

honey after extraction. The other elements however, all had their BP, AP and RT values

significantly deviating from their respective mean concentrations, implying that the

variations in composition of these elements can be attributed to both the farmer and the

retailers with regard to how they treated and stored the honey samples.

For Nkwanta, with the exception Co, Cr and K (with P>0.05) the differences in

concentration of all the elements were statistically significant at 95% confidence interval

(P<0.05). The LSD and Tukey analysis revealed that the other elements however, all had

their BP, AP and RT values significantly deviating from their respective mean

concentrations, implying that the variations in composition of these elements can be


84

attributed to both the farmer and the retailers with regard to how they treated and stored

the honey samples.

With the exception Cr and Cu (with P>0.05) the samples taken from Pankrono showed

statistically significant differences in concentrations of all the other elements (K, Ca, Na,

Mn, Al, Mg, V, Fe, Pb, Cr) at 95% confidence interval (P<0.05, ANOVA). For Co, the

LSD and Tukey analysis revealed that the RT values were far more than the mean, but the

BP and AP values were closer to the mean, implying that the changes in composition of

these elements can be attributed to how the Retailer treated the honey, after buying it from

the farmer. The other elements however, all had BP, AP and RT values significantly

deviating from their respective mean concentrations, implying that the variations in

composition of these elements can be attributed to both the farmer and the retailers with

regard to how they treated and stored the honey samples.

With the exception of Cr (with P>0.05) the samples taken from Ahwiaa showed statistically

significant differences in concentrations of all the other elements (K, Ca, Na, Mn, Al, Mg,

Cu, V, Fe, Cr) at 95% confidence interval (P<0.05, ANOVA). For K, the LSD and Tukey

analysis revealed that, BP values were far less than the mean, but the AP and RT values

were closer to the mean, implying that the changes in composition of these elements can

be attributed to how the farmer treated it, after extraction. For Cr, the RT values were far

more than the mean, but the BP and AP values were closer to the mean, implying that the

changes in composition of these elements can be attributed to how the Retailer treated it,

after buying it from the farmer. The other elements however, all had BP, AP and RT values


85

significantly deviating from their respective mean concentrations, implying that the

variations in composition of these elements can be attributed to both the farmer and the

retailers with regard to how they treated and stored the honey samples.

The null hypothesis (that the subsequent handling processes honey goes through after

harvesting has no significant effect on its composition) was therefore rejected.

4.3.5 Elemental Concentrations of Honey from Greater Accra Region

The highest concentration was observed for K (166.990-681.743 g/kg); Ca (23.926 –

157.577 g/kg); Na (900.214-5784.012 mg/kg); Mn (145.668-2566.847 mg/kg); Al (60.159-

523.148 mg/kg); Mg (75.697 – 350.144 mg/kg); Cu (4.524-288.298 mg/kg); V (1.001-

17.215 mg/kg); Fe (1.824-11.052 mg/kg); Pb (0.030-0.660 mg/kg); Co( 0.017-0.094

mg/kg) and Cr (0.036-0.078 mg/kg) in that order.

With the exception of Mg (Amasaman samples) , V (Pokuase samples), Cu (Adenta

samples) and Al (Adenta samples) where there was a decrease in concentration, all the

samples increased in concentration levels as they moved through the various routes (before

processing, after processing, and from the retailer) (Figures 4.5 to 4.116). The data were

subjected to Analysis of Variance (ANOVA) at 95% confidence Interval.

The variations in the concentrations of Pb, Fe, Mg, V, Cu, Al, Ca, Mn, and Na in all the

samples were statistically significant at 95% confidence Interval (P<0.05, ANOVA) (Table

B3, Appendix B). However, Co (in all the samples), Cr (Weija samples, Adenta samples,

Ablekuma samples) and K (sampled at Awoshie, Ablekuma, Afienya and Oyibi) did not


86

show significant variations in concentrations levels at 95% confidence interval. (P>0.05,

Table C3, Appendix C).

Those with significant differences in concentrations were further subjected to LSD and

Tukey analysis to determine whether the difference can be attributed to the samples

obtained from the farmer before processing, from the farmer after processing or from the

retailer (i.e those that deviated largely from the mean concentrations). It was found that,

the differences in concentrations of Pb, Fe, Mg, V and Cu, all deviated significantly from

their respective mean concentrations (Table 4.6). The null hypothesis (the processes honey

goes through after harvesting has no significant effect on its composition) was then

rejected. Similar deviations from the mean were also observed for Na, Ca, Mn, and K,

except the Na and Ca in samples collected at Oyibi, Mn in samples collected at Afienya,

and K in samples collected at Pokuase, Weija and Ayimensa, where only the samples

obtained from the retailer and from the farmer before processing deviated from the mean

concentrations (Table 4.6) respectively.


87

Figure 4.13: Concentration of Ca in all the samples analysed

-5

0

5

10

15

20

25

30

35

40

45

Conce

ntr

atio

n o

f C

a (g

/kg)

Sampling Sites

Concentration of Ca in all the Samples



88

Figure 4.14: Concentration of Mn in all the samples analysed

-5

0

5

10

15

20

25

30

35

40

45C

once

ntr

atio

n o

f M

n (

mg/k

g)

Sampling Sites

Concentration of Mn in all the Samples



89

Figure 4.15: Concentration of K in all the samples analysed

-5

0

5

10

15

20

25

30

35

40

45C

once

ntr

atio

n o

f K

(g/k

g)

Sampling Sites

Concentration of K in all the Samples



90

Figure 4.16: Concentration of Na in all the samples analysed

-5

0

5

10

15

20

25

30

35

40

45

Conce

ntr

atio

n o

f N

a (m

g/k

g)

Sampling Sites

Concentration of Na in all the Samples



91

4.4 Comparison of Elemental Compositions of Ghanaian Honey at the Various

Sampling Site

The samples collected from Brong Ahafo region recorded the highest levels of Ca, Al, V

and Cr. Since these essential elements are abundant in the earth’s crust (Taylor, 1964), they

may have been directly added by the bees during the honey production. The wooding and

metallic equipments used by the beekeepers might also have contributed to presence of

some metal levels in the honey. The levels of all the Co and Fe in the samples taken from

the various sampling sites in the Brong Ahafo region, showed significant deviations from

their respective mean concentrations, except the samples collected at Atebubu.

With the exception of the samples collected at Dumansua and Mantukwa, the

concentrations of all Cr, also deviated significantly from the mean concentrations. The

levels of Pb, V, Cu, Al, Ca, Mn, K and Na in all the sampling sites in the Brong Ahafo

region deviated significantly from the their respective mean concentrations. This imply that

the elemental composition of honey depends greatly on the environment in which the

samples are taken from, a fact that has been often considered in the elemental and

physiological studies of honey by researchers (Persano et al., 2004).

The samples collected from Ashanti region recorded the highest levels of Pb, Mg, K, Na

and Mn. The Pb may have been added from exhausts of automobiles due to the closeness

of most of the apiaries in the region to tarred roads. Mg, K, Na and Mn may have been

picked up by the bees during foraging, and added to the honey during production. With the

exception of Co (collected at Aboaso and Agona), Fe (collected at Pankrono), V (collected


92

at Aboaso), Al and Ca (collected at Fawode) all the other metals in the samples collected

from the various sites varied significantly from their respective mean concentrations.

The samples collected from Greater Accra region recorded the highest levels of Cu, Fe and

Co. Whiles some of these metals may have been added by the bees to the honey during

production, some may also have been added by the farmers during extraction. The Co and

Cr content in most of the samples did not differ significantly from their respective mean

concentrations. However, with the exception of Pb (collected at Amasaman), Fe (collected

at Weija and Ablekuma) and Al (collected at Weija), all the other metals in the honey

samples collected from the various sites varied significantly from their respective mean

concentrations. This also affirms that geographical origin has a significant effect on

honey’s composition (Persano et al., 2004).

4.5 Variations of Metal Content of Ghanaian Honey as it goes Through the Various

Processes

In general, potassium and calcium were the main elements, accounting for the majority of

the honey’s composition. Cadmium, mercury and arsenic were all below detection limit.

This might be because none of the sampling sites visited were in the vicinity of a

metallurgical or mining industry (Pendias et al., 1999).

There were some differences and similarities among the results. It was observed that, the

metal composition in most of samples analysed increased as the honey goes through

various processes or channels (from the farmers to the retailers). For instance, in the


93

samples taken from Atebubu in the Brong Ahafo region, Fe concentration before

processing was 3.756 mg/kg. The Fe concentration increased to 4.416 mg/kg after the same

honey was filtered into metal containers and later transferred into a gallon. When the same

honey was collected from a retailer who bought it directly from farmer, the Fe

concentration recorded was 6.792 mg/kg.

On the other hand, few of the samples analysed showed reduction in concentration along

the sampling chain. For instance, in the samples taken from Manpongten in the Ashanti

region, Ca concentration before processing was 120.960 g/kg. The Ca concentration

increased slightly to 121.130 g/kg after the same honey has been extracted from the comb

and sieved to remove bees and other bee products from it. When aliquots of the same honey

were sampled from a retailer who bought it directly from the farmer, the Ca concentration

recorded was 116.248 g/kg. The decrease in concentration may be attributed to adsorption

of the metals onto their storage containers.

As the Ghana Standard Authority (GSA) has not yet set allowable limits for the presence

of some metals (such as K, Cu, Fe, Ca, Na, V etc) in honey, noticeable contents of trace

metals cannot ascertain contamination with these metals.

Lead was detected in the entire sample, with the levels varying from 0.030 to 0.828 mg/kg.

However, these levels were less than the maximum limit sets by Ghana Standard Authority

(GSA) and Codex Alimentarius (1.0 mg/kg) for lead in honey. Presence of lead in the

freshly extracted honey may have been introduced into the honey from the emissions of

automobile exhaust gases (Kebede et al., 2012). Dust (containing lead particles) falling on


94

the unprocessed honey may have also contributed the levels of lead recorded in the samples

taken before processing.

Table 4.7: Accepted levels of some parameters in honey

Parameter/Element Limit/Range Organisations

pH 3.6-6.1 National Honey Board of USA

Electrical Conductivity <800µS/cm Council of European Union

Specific Gravity ~ 1.44 Food and Agricultural Organisation

Pb 1.0 mg/kg GSA/ Codex Alimentarius/WHO

As 0.1 mg/kg GSA/ Codex Alimentarius

Cd 0.1 mg/kg GSA/ Codex Alimentarius

Hg 0.1 mg/kg GSA/ Codex Alimentarius

Cu 0.216 mg/kg Italian Legislation

Cu 35 mg/kg Nigerian Standards

Mg 2 - 9 mg/day U.S. Department of Health and

Human Services

Fe 200-250 mg/kg of body

weight (lethal dose)

US Nuclear Regulatory Commision

Cr 20 – 50 µg/adults U.S. Dept. of Health and Human

Services

Source: GS Codex Stan 193:1995, Published by GSA in 2014; Mohamed et al., (2010); U.S. Dept. of Health

and Human Services (1999); USNRC (1979); Food and Agricultural Organisation (2007).

Increase in lead concentrations after processing maybe related to metal containers used or

from dust that contains lead falling onto them during processing. Further increase in the

lead concentrations of the honey bought from the retailers may be attributed to their storage

in improperly glazed pottery or leaded-crystal containers. (ATSDR, 1999).


95

Copper also was detected in all honey samples. As reported by the Agency for Toxic

Substances and Disease Registry, U.S. Department of Health and Human Services, copper

is necessary for good health. However, very large single or daily intakes of copper can

harm human health. It is one of the essential metals present in honey. It is not toxic if it is

present in a limited amount (Mohamed et al., 2010). Its concentration levels in this study

ranges from 4.524 to 288.298 mg/kg. Italian Standards set the allowable limit for the

presence of copper in honey at 0.216 mg/kg (Caroli et al., 1999) implying that all the honey

samples collected from the three regions were contaminated. On other hand, Polish

Standards and Nigerian Regulations have set a limit of 10 mg/kg (Roman et al., 2011) and

35 mg/kg (Adebiyi et al., 2004) for the presence of copper in honey sample. This also

implies that most of the honey samples collected from the three regions was contaminated.

Some of the Cu may have been picked up from the environment by the bees and added to

the honey during production. The increase in concentrations along the sampling routes may

be related to the medium and metal containers used by the beekeepers to process the honey

before they were sold in the market.

Vanadium was recorded in all the samples analyzed with a concentration range of 0.490 –

35.021 mg/kg. It is not yet known, the health effects in people of ingesting vanadium.

However, it is reported that an intake of over 10 mg of V per day can be toxic for adults;

the source is usually airborne anthropogenic V (WHO, 1996). Vanadium may have entered

the honey from natural sources; added by the bees during production, or from the burning

of fuel oils. The levels increased as it moved through the various processes. It may have

combine with other elements and particles, and found its way into the honey during


96

processing (ATSDR, 1992). There were few instances where the V concentration in the

honey from the retailers were lesser that of the freshly extracted honey. This may be as

result of the additives (mostly water) added to dilute the honey to increase its volume. The

reduction may also be attributed to adsorption of metals in the honey onto the containing

vessels or onto other contaminants such as charcoal. Heating of samples during heat-

extraction introduced contaminants such as charcoal into few of the honey samples

analysed.

Manganese is a component of living things, including both plants and animals, so

manganese is present in foods (including honey). Manganese was present in all the samples

analyzed with a concentration range of 75.697 – 681.236 mg/kg. The U.S. Department of

Health and Human Services reports that usual daily intakes range from about 2 to 9 mg/day.

Since manganese is abundant in the earth’s crust (Taylor, 1964), it may have also have been

added by the bees during production. Its levels increased along the farmer-to-trader routes.

Mg in the environment might have combined with other chemicals such as oxygen, sulfur,

and chlorine (NAS, 1973). As these can become suspended in air along with small dust

particles, they can find their way into the honey during processing.

Calcium and potassium are essential for living organisms. They are very reactive and

abundant in the earth’s crust (Taylor, 1964). They have numerous applications in the

chemical industries. All the honey samples analysed were rich in Ca and K with

concentration range from 2.393 – 283.690 g/kg and 112.933–1770.770 g/kg respectively.

Their levels increased slightly along the farmer-to-trader routes. The increment may be

attributed to the metals and woods used during extraction. At the sales point, recycled

mineral water bottles and gallons were used in honey’s storage. This may have accounted


97

for the further increase in Ca and K levels in honeys collected from the retailers, since some

of the containers were used without washing, or rinsed with water only. Washing containers

with soap and not rinsing properly can also affect the composition of the honey stored in

them since metals, such as Ca and Na are components of soap.

The Na, Mg, Cr levels recorded in honey may have also have been added by the bees during

production, since they are also abundant in the earth’s crust (Taylor, 1964). The increase

in the concentrations of these metals (Na, Mg, Cr) as the honey goes through the various

processes can be related to the extraction and treatment processes, equipment used and

nearness of apiaries to industries. Also, honey that comes into contact with metal containers

or equipments during storage or processing may have elevated levels of some metals

(Kebede et al., 2012). The mobility of some metals such as Co is moderately high at low

pH (ATSDR, 2004). All the honey samples analysed were acidic in character, therefore

some of the metals may have been absorbed from their storage containers into the honey

samples during storage.

With the exception of Cu, the levels of metals are in general within permitted limits set by

Ghana Standards Authority and other organizations such as Codex Alimentarius (Table

4.7). Any heavy metals present in honey above admitted levels by pollution standards, are

threats to human body through the possible negative effect of the contaminants (Kebede et

al., 2012). Therefore Ghanaian honey is therefore safe for human consumption with respect

to the elemental contamination.


98

4.6 Comparison of Elemental Composition of Honey from the Three Regions Studied

With Other Locations

A comparative analysis of the results obtained in this study with results of other studies

within and outside Ghana show that the range of elemental concentrations of honey from

these three regions of Ghana was averagely higher (Tables 4.8). Co and Hg in honey were

not reported by other studies that this work was compared to.

The levels of Ca in this study were higher than the concentration of Ca reported for honey

samples elsewhere in Ghana by Ankrah (1997). The concentrations of Fe recorded in this

studies (1.548 – 11.052 mg/kg) were however less than those recorded by Ankrah (1997)

(0.10 – 0.18 mg/kg). The levels of Ca and Fe in Ghanaian honey (this study) was

significantly higher than the concentration of Fe and Ca reported for honey samples outside

Ghana by other workers whose work this studies was compared with (Tables 4.8).

However, the values were far below what is considered to be a lethal dose of Fe in food

(200-250 mg/kg of body weight) as reported by US NRC (1979).

Only Agaja (2014) reported levels for Cr, which was higher than the values recorded in

this study for Cr in all the samples. The concentrations of V, Mg, Na, Ca and K in the

Ghanaian honey (this study) were also higher than their respective concentrations reported

for honey samples outside Ghana by other workers whose work this studies was compared.

The highest concentration of Al reported in honey samples in Nigerian honey (Agaja, 2014)

were far less than the values reported for this study. Al in honey was not reported by others,

but it was considered in this study. Of the workers compared with, only Mbiri et al., (2011)

reported levels of Cd, and As in honey samples in Kenyan honey. The values obtained in


99

this study for Cd and As were all less than 0.01 mg/kg, and also below the 0.02 mg/kg and

0.01 mg/kg respectively, reported in the Kenyan honey (Table 4.8).


100

Table 4.8: Comparison of Elemental Composition of Honey from the three Regions Studied with other Locations Metal Concentration Range (mg/kg)

This study Ghanaa Kenyab Nigeriac Nigeriad Polande Austriaf Germanyf Australiaf

Co 0.009 – 0.094 - - - - - 0.007 0.001 0.018

Pb 0.030 – 0.828 - 0.08 – 0.28 - - - 0.494 0.120 0.02

Cr 0.010 – 0.423 - - - - 0.0-6.1 - - -

Fe 1.548 – 11.052 0.1–0.18 - 136 - 407 - 0.0-18.6 4.717 6.301 4.345

V 0.490 – 35.021 - - - 4 - 13 - - - -

Cu 4.524 – 288.298 - 0.02 – 0.05 10 – 35 - - 0.498 0.164 0.033

Mg 75.697 - 681.236 - 12.64 – 41.88 - 21 -30 - - - -

Al 60.159 – 1186.369 - - - 7.0 - 25.0 - - - -

Mn 145.668 – 3501.004 - - 1 - 5 10 - 35 0.4 – 5.4 0.081 0.140 0.341

Na 900.214 – 8277.351 - 98.04 – 269.1 - 8 -1 2 - - -

Ca 2.393 – 283.690* 0.3–14.8 12.64 – 19.33 152 - 265 16.0 - 86.0 - - - -

K 112.933–1770.770* - 172.83– 781.52 1100- 21600 3.2-216 435.0 – 2694.0 - - -

As BDL - 0.02 – 0.03 - - - - - -

Hg BDL - - - - - - - -

Cd BDL - 0 – 0.02 - - - - - -

Analytical

procedure

INAA and AAS Titrimetry AAS and AES TRXRFS INAA TRXRFS AAS AAS AAS

*Concentrations in g/kg, a- Ankrah (1997), b- Mbiriet al., (2011), c- Adebiyi et al., (2004), d- Agaja (2014). e-Braziewicz et al., (2002), f-Bibi et al., (2008)


101

CHAPTER FIVE

5.0 CONCLUSIONS AND RECOMMENDATIONS

5.1 CONCLUSIONS

Fifteen elements comprising 8 essential elements (K, Fe, Mn, Ca, Cu, Na, Al, Mg) and 7

heavy metals (Cd, As, Hg, V, Co, Cr, Pb) were considered in this studies. Physicochemical

studies: pH, electrical conductivity and specific gravity were done prior to the elemental

analysis. All the honey samples were found to be acidic, with pH ranging from 3.6 to 6.1.

The acidity of honey is significant as it inhibits the growth of microorganisms. The

electrical conductivities ranged from 11.9 µS/cm to 44.4 µS/cm. They were within the

acceptable limits set by GSA and other organizations (< 800 µS/cm). The specific gravity

of the honey samples analysed ranged from 1.297 to 2.031. They were higher than the

values (1.2081 to 1.2270) reported in Libyan Honey (Mohamed et al., 2013). However,

these values were closer to the average specific gravity (1.44) value reported by the Food

and Agricultural Organisation (FAO, 2007). Cd, Hg and As in all the honey samples

analysed were below detection limit of 0.001 mg/kg.

In general, the concentrations of the metals in the honey samples analysed were observed

to differ significantly from one sampling site to another. This may be related to the

environment in which the apiaries are located. The honey samples analysed showed

significant variations in the concentrations of the metals as the honey goes through various

processes after extraction. Elemental concentrations in most of the honey samples

increased in concentration from the production line to the retailers. There were few

instances where the elemental concentrations of the honey samples reduced in


102

concentration along the sampling route. The variations may be related to the extraction

procedures and treatment processes such as filtering, sieving, hand-squeezing and heating

employed by the beekeepers during honey processing. The storage conditions and

packaging materials used by retailers are also possible sources of metals contaminants that

affects the composition of honey. Concentration of potassium in all the samples monitored

was the highest, followed by Ca. Concentrations of Co and Cr in all the samples were

generally low (< 1.0 mg/kg).

The concentrations of Mn, Na, K, Mg and Pb were highest in Ashanti region. The

concentrations of Ca, Al and Cr were highest in the Brong Ahafo region, whiles the samples

taken from Greater Accra region the highest concentrations of Cu, Fe, and Co. The metal

compositions of the honey in the various regions were of the order: K > Ca > Na > Mn >

Al > Mg > Cu > V > Fe > Pb > Co > Cr. The concentrations of the elements in the Ghanaian

honey studied were higher than results of metal concentrations in honey from other parts

of the world that this studies was compared with. All the metals studied, with the exception

of Cu were within the allowable limits set by various organizations (GSA, Codex

Alimentarius, WHO).

5.2 RECOMMENDATIONS

This study monitored the elemental composition of some Ghanaian honey from one

sampling site to another and as it goes from farmers to retailers. It has provided a

background data of how the various extraction, treatment, storage and handling processes


103

affects honey’s composition and consistency prior to reaching the consumer. The following

are recommended:

a. Due to high levels of some metals above recommended standards, it is suggested

that the Ghana Standards Authority, Ministry of Food and Agriculture, Food and

Drugs Authority and Food Research Institute should educate farmers on the best

ways of handling honey after extraction, to reduce the level of contamination.

b. Further studies should be conducted to investigate the sources of contaminants, the

rate at which the levels are accumulating, and its impacts on the quality of Ghanaian

honey.

c. A more comprehensive studies which would take into consideration how days,

times and seasons in which honey is harvested and processed affects its elemental

composition. This will provide background data on how these parameters affect the

composition of honey.

d. A study investigating heavy metals and physicochemical properties such as

moisture content, ash content, total acidity, reducing and non-reducing sugars, to

provide more data on the quality of Ghanaian honey.

e. A study, investigating other contaminants like pesticides, antibiotics,

polychlorinated biphenyls (PCBs), polynuclear aromatic hydrocarbons (PAHs),

microorganism levels in honey from all other regions of Ghana should be

conducted.

f. A more comprehensive (nationwide) sampling campaign recommended.


104

LIST OF REFERENCES

Acquarone, C., Buera, P. and Elizalde, B. (2007). Pattern of pH and electrical conductivity

upon honey dilution as a complementary tool for discriminating geographical origin of

honeys. Food Chemistry Vol. 101, p. 695-703.

Adebiyi, F. M., Akpan, I., Obiajunwa E. I. and Olaniyi H. B. (2004). Chemical/Physical

Characterization of Nigerian Honey. Pakistan Journal of Nutrition 3(5):278-291.

Adeyemo, D. J., Umar, I. M., Jonah S. A., Thomas, S. A., Agbaji, E. B and Akaho, E. H.

K. (2004). Trace elemental analysis of Nigerian Crude Oils by INAA using miniature

neutron source reactor. Journal of Radio Analytical and Nuclear Chemistry 261(1):229-

231.

Agaja, S. A. (2014). Instrumental Neutron Activation Analysis of Honey samples from

Lokoja and Suleija North Central Nigeria. Journal of Scientific Research and Reports 3(3):

419-426.

Agbagwa, O. E., Otokunefor, T.V. and Frank-peterside, N. (2011). Quality assessment of

Nigeria honey and Manuka Honey. Journal of Microbiology and Biotechnology Research

1(3):20-31.

Aidoo K (2005). ‘Bees for Development Honey Trade’. A Workshop held in Dublin,

Ireland in August 2005 and organised by Sasakawa Centre, University of Cape Coast. 1-4.

Ajibola A., Chamunorwa, J. P and Erlwanger, K. H. (2012). Nutraceutical values of natural

honey and its contribution to human health and wealth. Nutrition & Metabolism 9:61.

Al-Mamary, M., Al-Meeri, A., Al-Habori, M., 2002. Antioxidant activities and total

phenolics of different types of honey. Nutrition Research 22, 1041–1047.

Al-Waili, N.S. (2003). Effects of daily consumption of honey solution on hematological

indices and blood levels of minerals and enzymes in normal individuals. Journal of

Medicinal Food 6:135–140.

Andrade, P., Amaral, M., Isabel, P., Carvalho, J., Seabra, R., and Cunha, A. (1999).

Physicochemical attributes and pollen spectrum of Portuguese heather honeys. Food

Chemistry 66, 503–510.


105

Anklam, E. (1998). A review of the analytical methods to determine the geographical and

botanical origin of honey. Food Chemistry 63,549–562.

Ankrah, E. K. (1997). Chemical composition of some Ghanaian honey samples. Ghana

Journal of Agricultural Science Vol. 31, p119-131. Apidologie 35:S38-S81.

ANL (Argonne National Laboratory). (2005). Human Health Fact Sheet.

Ashkin, E. and Mounsey, A. (2013). A spoonful of honey helps a coughing child sleep.

The Journal of Family Practice 62(3): 145–147.

ATSDR (Agency for Toxic Substances and Diseases Registry). (1992, 1999, 2004).

Toxicological Profile for Elements. Atlanta, GA, United States Department of Health and

Human Services, Public Health Service.

Barceloux, D. C. (1999). Cobalt. Clinical Toxicology 37(2); 201-216.

Baroni, M. V., Arrua, C., Nores, M. L., Fayé, P., Díaz, M. D. P., Chiabrando, G. A. and

Wunderlin, D. A. (2009). Composition of honey from Córdoba (Argentina): Assessment

of North/South provenance by chemometrics. Food Chemistry. 114, 727.

Bibi, S., Husain, S. Z. and Malik, N. R. (2008). Pollen analysis and heavy metals detection

in honey samples from seven selected countries. Pakistan Journal of Botany 40(2): 507-

516.

Blasa, M., Candiracci, M., Accorsi, A., Picentini, M. P., Albertini, M. C. and Piatti, E.

(2006). Raw Millefiori honey is packed full of antioxidants. Food Chemistry 97, 217-222.

Bogdanov, S. (2006). Contaminants of bee products. Apidologie, Springer Verlag

(Germany). 37 (1), pp.1-18. <hal-00892166>

Bogdanov, S., Jurendic, T., Sieber, R. and Gallmann, P. (2008). Honey for nutrition and

health: a review. The Journal of the American College of Nutrition 27(6):677-89.

Bogdanov, S.A., Indorf, J., Charriere, P., Fluri, and Kilchermann, V. (2003). The

contaminants of the bee colony. Swiss bee Research Centre. Bern, Switzerland. pp 12.

Braziewicz, J., Fijal, I., Czyziewski T., Jaskola, M., Korman, A., Banas, D., Kubala-Kukus

A., Majewska, U. and Zemlo, L. (2002). PIXE and XRF analysis of honey samples.

Nuclear Instruments and Methods in Physics Research 187; 231-237.


https://www.google.com.gh/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjC1ITQosXKAhWGXhoKHfWJD30QFggaMAA&url=http%3A%2F%2Fwww.jfponline.com%2F&usg=AFQjCNEJEx1CkEAbcg_83TJO5Fd8xZmtmA&bvm=bv.112454388,d.d2s

106

Buldini, P. L., Cavali, A., Mevoli, and Sharma, J.L. (2001). Ion Chromatographic and

Voltammetric determination of heavy and transition metals in honey. Food chemistry

(73):487-495.

Callender, E. (2003). Treatise on Geochemistry. In B. S. Lollar, H. D. Holland and K. K.

Turekian(Ed.). 9:67-105. Amsterdam: Elsevier Science Publishers.

Carapella, S. C. (1992). Arsenic and Arsenic Alloys. In J. K. Kroschwitz and M. Howe-

Grant. (Eds.) Kirk-Othmer Encyclopaedia of Chemical Technology 3:624-633.

Caroli, S., Forte, G., Iamiceli, A. L., and Galoppi, B. (1999). Determination of essential

and potentially toxic trace elements in honey by inductively coupled plasma-based

techniques. Talanta 50(2), 327–336.

Celli, G., Maccagnani. (2003). Honey bee as bioindicators of environmental pollution.

Bulletin of Insectology (56):137-139.

Chepulis, L. M., Starkey, N. J., Waas, J. R. and Molan, P. C. (2009). The effects of long

term honey, sucrose or sugar-free diets on memory and anxiety in rats. Physiology and

Behaviour 97:359–368.

Chalhoub, C., Lydakis – Simantiris, N., Naxakis, G., Arvanitoyannis, I. and Gotsiou, P.

( 2007). Mineral Content Analysis of Greek Honey by Inductively Coupled Plasma Atomic

Emission Spectroscopy (icp-aes): a Tool for Botanical and Geographical Discriminations.

(Assessed on August 15, 2014 13:50 CET.

lydakis.chania.teicrete.gr/Δημοσιεύσεις/.../metals_poster_Rio_2007.ppt)

Codex Almentarius Commission. (1983/84). Proposed Codex Standard for Honey. (Rome:

FAO/WHO) CX/PFV84/13.

Codex Alimentarius Commission. (2001). Codex Alimentarius Standard for Honey,

CODEX STAN 12-1981, FAO and WHO, Rome. 1-8.

Conti, M. E. (2000). Lazio region (Central Italy) Honeys: A Survey of Mineral Content

and Typical Quality Parameters. Food Control 11: 459-463.


107

Costa, L., Albuquerque, M., Trugo, L., Quinteiro, L., Barth, O.,Ribeiro, M., & De Maria,

C. (1999). Determination of non-volatile compounds of different botanical origin Brazilian

honeys. Food Chemistry 65, 347–352.

Cui, R., Li, B., Suemaru, K., Watanabe, S., Okihara, K., Hashimoto, K., Yamada, H., and

Araki, H. (2008). Topical application of royal jelly has a healing effect for 5-fluorouracil

induced experimental oralmucositis in hamsters. Methods and Findings in Experimental

and Clinical Pharmacology. 30(2):103–6.

De-Corte, F., A. Simonits, A. De-Wispelaere and Hoste, J. (1987). Accuracy and

applicability of the k standardization method. Journal of Radioanalytical and Nuclear

Chemistry. 113:145-165.

Denton, G. R. W., Bearden, B. G., Concepcion, L. P., Siegrist, H. G., Vann, D. T. and

Wood, H. R. (2001). Contaminant Assessment of Surface Sediment from Tanapag Lagoon,

Saipan. Water and Environmental Research Institute of the Western Pacific. Univeristy of

Guam, Mangilao, Guam. Techical Report No. 93.

De-Rodrı´guez, G.O., de Ferrer, B.S., Ferrer, A. and Rodrı´guez, B. (2004).

Characterization of honey produced in Venezuela. Food Chemistry 84: 499-502.

Dustmann, J. H. (1993). Honey, quality and its control. American Bee Journal 133(9),

648–651.

Emma, M. and Susana, P. (2006). Determination of heavy metals in honey by

potentiometric stripping analysis and using a continuous flow methodology. Food

Chemistry 94; 478–483.

Encyclopedia Britannica. (2012). Ultimate Reference Suite. Encyclopedia Britannica Inc.,

London, 15th Ed.

EPA (Environmental Protection Agency). (1984, 2011). Final Assessment Document for

Elements. Final Draft. Cincinnati, OH: US. Environmental Protection Agency, Office of

Research and Development.

Finkelman, R. B. (2005). Sources and Health Effects of Metals and Trace Elements in Our

Environment: An Overview. In T.A Moore,A. Black, J. A Centeno, J. S Harding and D. A.

Trumm.


https://www.google.com.gh/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwid8bWTwNvJAhVBKA8KHZ59BlEQFggaMAA&url=http%3A%2F%2Flink.springer.com%2Fjournal%2F10967&usg=AFQjCNGJ2lXJdO_UknD8jPBCUpRCac8LWg

https://www.google.com.gh/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwid8bWTwNvJAhVBKA8KHZ59BlEQFggaMAA&url=http%3A%2F%2Flink.springer.com%2Fjournal%2F10967&usg=AFQjCNGJ2lXJdO_UknD8jPBCUpRCac8LWg

108

Fisher, R. A. (1971) (1935). The Design of Experiments. (9th edition). Macmillan. ISBN

0-02-844690-9.

FAO (Food and Agricultural Organisation). (2012). Bees and their role in forest

livelihoods. Pp. 1-8. Available at: ftp://ftp.fao.org/docrep/fao/012/i0842e/i0842e10.pdf.

(Assessed on 18th November, 2014, 15:00 CET).

FAO (Food and Agricultural Organisation), Corporate Document Repository. (2003). Non-

Wood Forest Products In Ethiopia. Pp. 1-5. Available at:

http://www.fao.org/docrep/003/x6690e/X6690E01.htm. (Assessed on 18th November,

2014, 14:42 CET).

FAO (Food and Agricultural Organisation), Corporate Document Repository. (2007).

Value-added Products From Beekeeping. Pp 1-15. Available at:

http://www.fao.org/docrep/w0076e/w0076e04.htm. (Assessed on 18th November, 2014,

14:39 CET).

Francis, C. D. and Forsyth, C. (2005). Toxicity Profile of Manganese. (Viewed on

November 1, 2014. 14;12 CET. Available at: http://rais.ornl.gov/tox/profiles/mn.shtml).

(Assessed on 18th November, 2014, 14:43 CET).

Frankel, S.M., Robbinson, G.E. and Berenbaum, M.R. (1998). Antioxidant capacity and

correlated characteristics of 14 unifloral honeys. Journal of Apicultural Research 37:27–

31.

Funk, W., Dammann, V. and Donnevert, G. (2007). Quality Assurance in Analytical

Chemistry: Applications in Environmental, Food, and Materials Analysis, Biotechnology,

and Medical Engineering. 2nd Edition. Pp. 115-194.

Gomes, S., Dias, L. G., Moreira, L. L., Rodrigues, P. and Estevinho, L. (2010).

Physicochemical, microbiological and antimicrobial properties of commercial honeys from

Portugal. Food and Chemical Toxicology 48: 544–548.


http://www.fao.org/docrep/003/x6690e/X6690E01.htm

http://www.fao.org/docrep/w0076e/w0076e04.htm

109

Gonzales, A. P., Burin, L. and del Pilar Buera, M. (1999). Color changes during storage of

honeys in relation to their composition and initial color. Food Research International 32,

185-191.

Goyer, R. (1991). Toxic Effects of Metals. In: M. O. Amdur, J. D. Duoll and C, D. Klassen,

Eds. Casarett and Duoll’s Toxicology. 4th ed. Pergamon Press, New York, pp. 623-680.

Guler, A., Bakan, A., Nisbet, C. and Yavuz, O. (2007). Determination of important

biochemical properties of honey to discriminate pure and adulterated honey with sucrose

(Succharum officinarum L.) syrup. Food Chemistry 105, 1119-1125.

Hamidatou, L., Slamene, H., Akhal, T., Begaa, S., Messaoudi, M. and Boussaad, Z. (2013).

NAA Algerian Laboratory Evaluation Processed by WEPAL and IAEA during 2011-2012.

Journal of Analytical Sciences, Methods and Instrumentation 3, 184-192.

Hase, S., Suzuki, O., Odate, M. and Suzuki S. (1973). Changes in quality of honey on

heating and storage. I. Changes in hydroxymethylfurfural (HMF) content of honey. Journal

of Food Science and Technology 20:248–256.

IAEA-TECDOC. (2001). Quality aspects of research reactor operations for instrumental

neutron activation analysis held in Accra, Ghana. Report of an Advisory Group meeting

18–22 October, 2001; 1218.

IARC (International Agency for Research on Cancer). (1991). International Agency for

Research on Cancer Monographs on the Evaluation of Carcinogenic Risks to Humans.

Chlorinated Drinking-water, Chlorination by-product, some other halogenated

compounds; cobalt and cobalt compounds. Lyon, France. Vol. 86.

IARC (International Agency for Research on Cancer). (1980). International Agency for

Research on Cancer Monographs on the Evaluation of Carcinogenic Risks to Humans.

Some Metals and Metallic compounds. Lyon, France. Vol. 23.

Jones, K. C. (1987). Honey as an indicator of heavy-metal contamination. Water Air and

Soil Pollution 33(1-2), 179–189.


110

Kabata-Pendias, A. and Pendias H. Biogeochemistry of Trace Elements. 1999, PWN,

Warszawa. 74-288.

Karaman, T., Buyukunal, S. K., Vurali, A. and Altunatmaz, S. S. (2010). Physico-chemical

properties in honey from different regions of Turkey. Food Chemistry 123:41-44.

Kebede, N., Subramanian, P.A. and Gebrekidan, M. (2012). Physicochemical analysis of

tigray honey: An attempt to determine major quality markers of honey. Bulletin of the

Chemical Society of Ethiopia 26(1), 127-133.

Kegley, S. E., Hill, B. R., Orme, S. and Choi, A. H. (2009). Copper. PAN Pesticide

Database. North America (San Francisco, CA): Pesticide Action Network. Available at:

http:www.pesticideinfo.org. (Assessed on November 22, 2014).

Komarnicki, G. J. K. (2005). Lead and Cadmium in Indoor Air and the Urban Environment.

Environmental Pollution 136: 47-61

Kpeglo, D. O., Lawluvi, H., Faanu, A., Awudu, A. R., Arwui, C.C., Deatanyah, P.,

Wotorchi-Gordon S., Darko, E. O., Emi-Reynolds, G., Opata, N. S. and Baidoo, I. K.

(2012). Radiochemical Pollutants Concentration in Ghana Cement by Instrumental

Neutron Activation Analysis and Gamma-Ray Spectrometry. Research Journal of

Environmental and Earth Sciences 4(1):99-104.

Kucuk, M., Kolayli, S., Karaoglu, S., Ulusoy, E., Baltaci, C. and Candan, F. (2007).

Biological Activities and Chemical Composition of three Honeys of Different Types from

Anatolia. Food Chemistry. 100: 526 - 534

Kwapong, P. K., Ilechie, A. A. and Kusi, R.J. (2013). Comparative antibacterial activity of

stingless bee honey and standard antibiotics against common eye pathogens. Journal of

Microbiology and Biotechnology Research 3(2):9-15.

Lachman, J., Kolihova, D., Miholova, D., Kosata, J., and Titera, D. and Kult, K. (2007).

Analysis of minority honey components: possible use for the evaluation of honey quality.

Food Chemistry 101, 973-979.

Linton, L.R. and Harder, L.D. (2007). Biology 315 – Quantitative Biology Lecture Notes.

University of Calgary, Calgary, AB.


111

Mbiri, A., Onditi, A., Oyaro, N., and Murago, E. (2011). Determination of essential and

heavy metals in Kenyan honey. Journal Of Agriculture, Science And Technology Vol.

13(1), 108-115.

MDH (Minnesota Department of Health). (2006). Copper in Drinking water, Health Effects

and How to Reduce Exposure. Available at:

http://healthstate.mn.us/dirs/eh/water/com/fs/copper.html. (Assessed on November 22,

2014).

Merian, E. (1984). Introduction on Environmental Chemistry and Global Cycles of

chromium, nickel, cobalt, beryllium, arsenic, cadmium and selenium and their Derivatives.

Toxicology and Environmental Chemistry Vol. 8.No. 1. Pp. 9-38.

Milestone’s Application Note; Microwave Acid digestion Cookbook. (1996). Milestone

Lab Systems. Report Codes 23 and 99.

Mohamed, H. S. A., Saleh, E., Ali A., Mohamed, E. and Nagwa, H. S. A. (2013).

Physicochemical, Heavy Metals and Phenolic Compounds Analysis of Libyan Honey

Samples Collected from Benghazi during 2009-2010. Food and Nutrition Sciences 4, 33-

40.

NAS (National Academy of Science). (1973). Manganese in Ecosystem. Medical and

Biological Effects of environmental Pollutants: Manganese. Washington, DC: National

Academy of Science 3-50.

NHB (2015). “Honey’s Natural Benefit”. National Honey Board, Longmont Colorado.

www.nhb.org. Retrieved March, 2015.

Ouchemoukh, S., Louaileche, H. and Schweitzer, P. (2007). Physicochemical

characteristics and pollen spectrum of some Algerian honeys. Food Control 18, 52-58.

Patnaik, P. (2004). Preliminary Operations of Analysis. Dean’s Analytical Chemistry

Handbook, Chapter (McGraw-Hill Professional). Access Engineering. 2nd Ed. pp. 204-

500.


http://healthstate.mn.us/dirs/eh/water/com/fs/copper.html

112

Pérez-Arquillué, C., Conchello, P., Ariño, A., Juan, T., and Herrera, A. (1995).

Physicochemical attributes and pollen spectrum of some unifloral Spanish honeys. Food

Chemistry 54, 167–172.

Persano, O. L. and Piro, R. (2004). Main European unifloral honeys. Descriptive sheets.

Apidologie. 35: S38–S81.

Pohl, P. (2009). Determination of metal content in honey by atomic absorption and

emission spectrometries. TraC Trends in Analytical Chemistry. Vol. 28, No. 1. pp. 117-

128.

Porrini, C., Sabatini, A.G., Girotti S., Ghini, S., Medrzycki, P., Grillenzoni, F., Bortolotti,

L., Gattavecchia, E. and Celli, G. (2003). Honeybees and bee products as monitors of the

environmental contamination. Apiacta 38:63–70.

Radojevic, M. and Bashkin, V. N. (1999). Practical Environmental Ananlysis. RSC, UK.

300-469

Rodriguez-Otero, J., Paseiro, P., Simal, J., Terradillos, L., & Cepada,A. (1992).

Determination of Na, K, Ca, Mg, Cu, Fe, Mn and total cationic milliequivalents in spanish

commercial honeys. Journal of Apicultural Research 31(2), 65–69.

Roman, A., Madras-Majewska, B. and Popiela-Plebau, E. (2011). Comparative Study Of

Selected Toxic Elements in Propolis and Honey. Journal of apicultural Science Vol. 55.

No. 2.

Ron, E. Z., Minz, D., Finkelstein, N. and Rosecnberg, E. (1992). Introduction of Bacteria

with Cadmium. Biodegradation 3: 161-171.

Ruschioni, S., Riolo, P., Minuz, R. L., Stefano, M., Cannella, M., Porrini, C. and Isidoro,

N. (2013). Biomonitoring with Honeybees of Heavy Metalsand Pesticides in Nature


113

Reserves of the Marche Region (Italy). Biological Trace Elements Research DOI

10.1007/s12011-013-9732-6

Sadia, B., Syed, Z. H. and Riffat, N. M., (2008). Pollen Analysis and Heavy Metals

Detection in Honey Samples From Seven Selected Countries. Pakistan Journal of Botany

40(2): 507-516.

Saeed, H. M. (1998). Application of new technologies in Canary honeys for typing and

quality control. Bulletin of Environmental Contamination and Toxicology 80, pp 30–33.

Sanna, G. M., Pilo, P., Piu, A., Tapparo, A. and Seeber, R. (2000). Determination of heavy

metals in honey by anodic stripping voltammetry at microelectrodes. Analytica Chimica

Acta 415:165-173.

Saxena, S., Gautam, S., Sharma, A. (2010). Physical, biochemical and antioxidant

properties of some Indian honeys. Food Chemistry 118, 391-397.

Schetz, Joseph A.; Allen E. Fuhs (1999-02-05). Fundamentals of fluid mechanics. Wiley,

John & Sons, Incorporated. pp. 109-144.

Schramm, D.D., Karim, M., Schrader, H.R., Holt, R.R., Cardetti, M., and Keen, C.L.

(2003). Honey with high levels of antioxidants can provide protection to healthy human

subjects. Journal of Agricultural and Food Chemistry 51:1732–1735.

Sedgwick, J. S. (2005). Contamination and Remediation of Soil at a Former Orchard Site,

Hamilton, North Island, New Zealand. Thesis, University of Waikato.

Singh, N. and Bath, P. K. (1997). Quality Evaluation of Different Types of Indian honey.

Food Chemistry 58; No. 1-2. pp. 129-133.


114

SNV (Stichting Nederlandse Vrijwilligers, Netherlands Development Organisation,

Ghana). (2010). The Honey Industry in Ghana: An Overview. Synthesis Report. Final

Version pp. 6-48.

Somenath, M. (2003). Sample Preparation Techniques in Analytical Chemistry. ISBN 0-

471-32845-6. John Wiley & Sons, Inc.

Sporns, P., Plhak, L., aand Friedrich, J. (1992). Alberta honey composition. Food

Research International 25, 93–100.

Swallow, K., and Low, N. (1990). Analysis and quantitation of the carbohydrates in honey

using high-performance liquid chromatography. Journal of Agricultural Food Chemistry

38, 1828–1832

Taylor, S. R. (1964). Abundance of Chemical Elements in the Continental Crust: A New

Table. Geochimica et Cosmochimica Acta 28: 1273-1285.

Terrab, A., Hernanz, D., and Heredia, F.J. (2004). Inductively coupled plasma optical

emission spectrometric determination of minerals in thyme honeys and their contribution

to geographical discrimination. Journal of Agricultural and Food Chemistry 52:3441-

3445.

The Council of the European Union. Council Directive 2001/110/EC of 20 December

2001 Relating to Honey. Official Journal of the European Communities Vol. L10, 2002,

pp.47-52. Available at:

http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2002:010:0047:0052:EN:P

DF. (Assessed on November 12, 2015. 13:56 CET)

Tong, S.C., Morse, R.A., Bache, C.A. and Lisk, D.J. (1975). Elemental analysis of honey

as an indicator of pollution; Forty-seven elements in honeys produced near highway,

industrial, and mining areas. Archives of Environmental Health 30 (7):329-32.

Tukey, J. (1949). "Comparing Individual Means in the Analysis of Variance". Biometrics

5 (2): 99–114. JSTOR 3001913.


https://www.google.com.gh/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0ahUKEwidlKLxs8XKAhXMuhoKHUfqBVgQFgg1MAU&url=http%3A%2F%2Fwww.ghanayello.com%2Fcompany%2F32123%2FSNV_Netherlands_Development_Organisation&usg=AFQjCNFWa5H2T_g2IBDjmqMTPjtkuenmlw&bvm=bv.112454388,d.d2s

https://www.google.com.gh/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0ahUKEwidlKLxs8XKAhXMuhoKHUfqBVgQFgg1MAU&url=http%3A%2F%2Fwww.ghanayello.com%2Fcompany%2F32123%2FSNV_Netherlands_Development_Organisation&usg=AFQjCNFWa5H2T_g2IBDjmqMTPjtkuenmlw&bvm=bv.112454388,d.d2s

115

Tuzen, M. Silici, S. Mendil, D. and Soylak, M. (2007) Trace element levels in honeys from

different regions of Turkey. Food Chemistry 103; 325-330.

US NRC (National Research Council). (1979). Iron. Baltimore, MD: University Park Press.

Vallee, B. L. and Auld, D. S. (1990). Zinc Coordination, Function and Structure of Zinc

Enzymes and Other Proteins. Biochemistry 29: 5647-5659.

Varian booklet. (1997). Introducing Atomic Absorption Analysis, Publication number

8510055700, Varian Australia Pty Ltd, A.C.N. 004 559 540, January 1997. pp, 1-4

Virkutyte, J. and Sillanpa, M. (2006). Clinical Evaluation of Potable Water in Eastern

Qinghai Province, China: Human Health Aspects. Environment International 32:80-86.

Wikipedia (2015). Post hoc Analysis. Available at:

https://en.wikipedia.org/wiki/Post_hoc_analysis (Assessed on 18th November, 2014,

15:30 CET).

White, J.W. Jr. (1975). Composition of Honey. In: Honey – A Comprehensive Survey

(Crane, E. Editor). Heinemann, London UK. pp. 157–206.

WHO (World Health Organisation). (1996). Trace Elements in Human Nutrition and

Health. Geneva. pp. 72-143

Wotton, M. (1976, 1978). Effect of accelerated storage conditions on the chemical

composition and properties of Australian honeys. 23-28, 167-172.

Yilmaz, H., and Yavuz, O. (1999). Content of some trace metals in honey from south-

eastern Anatolia. Food Chemistry 65:475-476.

Young, R. (2005). Toxicity Profile of Cadmium. Available at:

http://rais.ornl.gov/tox/profiles/cadmium.html. (Assessed on Januanry 25, 2015. 14:12

CET).


http://rais.ornl.gov/tox/profiles/cadmium.html

116

APPENDIX

APPENDIX A

Figure A1: Linear Regression Line for Calibration of AAS for Analysis of Co

Figure A2: Linear Regression Line for Calibration of AAS for Analysis of Pb

0

0.0688

0.1407

0.3488y = 0.0698x - 8E-05

R² = 1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 1 2 3 4 5 6

Abso

rban

ce

Concentration of Co (mg/L)

Linear Regression Line for Calibration of AAS for Analysis of Co

0

0.1429

0.3879

0.7751y = 0.078x - 0.005

R² = 0.9997

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 2 4 6 8 10 12

Abso

rban

ce

Concentration of Pb (mg/L)

Linear Regression Line for Calibration of AAS for Analysis of Pb


117

APPENDIX A

Figure A3: Linear Regression Line for Calibration of AAS for Analysis of Cr

Figure A4: Linear Regression Line for Calibration of AAS for Analysis of Fe

0

0.072

0.1405

0.3376y = 0.0672x + 0.0031R² = 0.9996

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 1 2 3 4 5 6

Abso

rban

ce

Concentration of Cr (mg/L)

Linear Regression Line for Calibration of AAS for Analysis of Cr

0

0.1375

0.3518

0.6976y = 0.0699x - 0.0003

R² = 1

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 2 4 6 8 10 12

Abso

rban

ce

Concentration of Fe (mg/L)

Linear Regression Line for Calibration of AAS for Analysis of Fe


118

APPENDIX B

Table B1: Results of the elemental composition of honey from the Brong Ahafo region

BRONG AHAFO REGION

ELEMENT Atebubu Fiapre Drobo Dumasua Mantukwa Nsoatre Kintampo Techiman Tanoso Berekum

Co BP 0.029 0.036 0.040 0.037 0.026 0.033 0.036 0.023 0.009 0.027

(mg/kg) AP 0.039 0.036 0.040 0.037 0.026 0.033 0.037 0.030 0.012 0.027

RT 0.039 0.036 0.040 0.037 0.026 0.036 0.086 0.036 0.013 0.036

Pb BP 0.096 0.552 0.408 0.414 0.168 0.186 0.270 0.306 0.582 0.402

(mg/kg) AP 0.234 0.636 0.504 0.498 0.390 0.258 0.552 0.444 0.606 0.576

RT 0.324 0.672 0.540 0.523 0.426 0.342 0.588 0.510 0.678 0.612

Cr BP 0.040 0.043 0.042 0.036 0.036 0.033 0.046 0.027 0.026 0.042

(mg/kg) AP 0.050 0.046 0.048 0.047 0.042 0.036 0.423 0.036 0.036 0.042

RT 0.050 0.046 0.171 0.423 0.046 0.046 0.423 0.047 0.048 0.046

Fe BP 3.498 3.756 2.598 5.436 3.012 3.504 3.096 4.116 2.496 3.180

(mg/kg) AP 3.924 4.416 3.252 6.066 3.648 4.014 3.222 4.416 2.766 3.282

RT 4.302 6.792 3.690 6.174 3.786 4.242 3.408 5.298 2.808 3.678

Mg BP 540.369 534.958 391.115 336.147 424.369 401.236 302.015 379.256 381.224 368.055

(mg/kg) AP 541.688 535.838 395.545 340.985 430.616 406.325 309.016 385.805 387.224 379.956

RT 545.336 552.369 400.2365 342.258 436.258 408.369 314.357 385.902 388.889 401.629

V BP 30.259 21.258 17.235 20.158 8.032 23.369 30.142 17.215 29.358 17.125

(mg/kg) AP 34.565 34.485 18.762 21.063 8.721 23.662 30.284 17.772 32.148 18.672

RT 35.021 34.125 26.369 22.369 10.025 29.191 32.159 17.777 32.190 25.162

Cu BP 195.001 18.063 11.418 5.325 20.147 85.369 4.991 106.047 101.365 74.148

(mg/kg) AP 195.082 19.502 12.110 6.911 21.673 85.387 5.140 106.211 101.680 82.361

RT 203.265 23.116 16.248 8.269 26.024 88.147 18.917 108.124 101.900 88.144

Al BP 1163.025 238.027 421.774 481.302 190.365 175.369 553.478 444.018 310.258 200.115

(mg/kg) AP 1174.176 239.953 426.806 483.067 192.282 176.265 577.896 444.856 311.201 196.062

RT 1186.369 263.258 469.235 489.369 201.364 186.325 641.668 447.314 316.005 219.248


119

BP-Before Processing, AP- After Processing, RT-Retailer

As, Hg, and Cd were Below Detection Limit of 0.001 mg/kg

BRONG AHAFO REGION

ELEMENT Atebubu Fiapre Drobo Dumasua Mantukwa Nsoatre Kintampo Techiman Tanoso Berekum

Ca BP 221.581 179.52 170.10 157.74 59.614 74.25 162.67 151.82 90.26 110.99

(g/kg) AP 236.271 182.44 173.46 166.88 62.135 75.69 176.45 151.93 91.88 110.05

RT 283.690 230.08 186.49 191.21 68.184 79.98 193.22 152.06 93.65 203.25

Mn BP 1808.795 1616.258 3460.008 1707.725 1339.216 1406.877 1991.350 2102.147 1499.3658 2001.048

(mg/kg) AP 1826.274 1641.246 3468.520 1821.273 1344.201 1477.021 1992.298 2153.322 1508.368 2002.300

RT 1833.256 1702.856 3474.237 2001.156 1386.315 1481.985 1996.994 2162.195 1512.325 2009.125

K BP 281.19 294.50 1453.397 475.00 182.64 560.07 112.933 340.22 424.61 1101.56

(g/kg) AP 283.01 294.63 1453.442 475.08 189.63 560.21 112.971 341.01 425.00 1101.63

RT 283.16 294.89 1453.454 475.29 190.51 566.58 113.034 342.23 425.99 1101.97

Na BP 4613.258 4726.118 5822.164 3942.023 4809.166 4111.024 3702.298 3796.159 2993.418 4759.862

(mg/kg) AP 4670.819 4740.251 5900.331 3948.639 4825.036 4216.158 3799.037 3811.370 2996.600 4765.635

RT 4688.009 4746.947 5919.315 3949.997 4901.478 4304.157 3831.625 3824.160 3011.152 4800.974


120

APPENDIX B

Table B2: Results of the elemental composition of honey from the Ashanti region

ASHANTI REGION

ELEMENT Ntonso Jamasi Aboaso Mampong-

ten

Nkwanta Fawode Ahwiaa Agona Pankro-

no

Asenua

Co BP 0.013 0.014 0.026 0.030 0.063 0.013 0.033 0.026 0.016 0.040

(mg/kg) AP 0.013 0.030 0.036 0.037 0.066 0.039 0.036 0.030 0.023 0.059

RT 0.013 0.036 0.036 0.037 0.066 0.059 0.130 0.036 0.037 0.087

Pb BP 0.624 0.480 0.090 0.264 0.330 0.402 0.486 0.120 0.156 0.228

(mg/kg) AP 0.678 0.516 0.162 0.432 0.366 0.540 0.540 0.402 0.174 0.270

RT 0.828 0.528 0.204 0.444 0.396 0.606 0.594 0.486 0.342 0.402

Cr BP 0.010 0.333 0.033 0.054 0.047 0.041 0.041 0.048 0.023 0.017

(mg/kg) AP 0.042 0.336 0.033 0.297 0.048 0.042 0.041 0.048 0.027 0.026

RT 0.043 0.378 0.037 0.301 0.048 0.054 0.045 0.054 0.037 0.040

Fe BP 1.548 4.242 4.080 2.496 1.644 3.198 2.094 2.880 3.090 4.338

(mg/kg) AP 1.794 4.332 4.112 2.928 1.662 3.204 2.208 3.006 3.108 4.464

RT 2.508 4.812 4.226 4.530 1.884 3.792 2.358 3.108 3.402 4.584

Mg BP 401.236 323.158 97.369 192.902 311.258 207.158 429.369 509.265 659.216 144.325

(mg/kg) AP 407.286 325.394 99.365 193.268 312.268 208.369 444.256 516.351 674.181 146.132

RT 447.325 342.145 103.268 199.235 333.258 219.375 448.365 519.247 681.236 151.369

V BP 3.128 9.711 6.020 13.258 9.325 3.254 7.325 0.490 4.930 3.120

(mg/kg) AP 5.167 9.992 6.119 14.512 10.112 3.961 8.112 0.498 4.932 3.224

RT 6.662 16.257 6.183 19.268 13.258 8.254 12.367 0.523 7.325 5.198

Cu BP 15.256 186.424 80.135 5.186 73.152 49.214 24.003 17.249 9.226 102.135

(mg/kg) AP 16.560 191.833 86.258 8.451 74.128 55.235 24.143 17.252 10.831 109.462

RT 13.211 192.666 86.542 11.254 77.462 57.235 24.165 11.168 11.161 111.028

Al BP 261.862 249.003 316.884 223.687 304.100 280.157 243.117 233.926 509.279 242.369

(mg/kg) AP 276.934 249.076 316.998 228.034 304.127 283.200 247.144 236.804 506.208 244.003

RT 300.119 256.312 318.258 236.125 316.200 285.159 268.265 277.178 576.354 247.315

Ca BP 70.032 149.891 120.960 121.866 62.224 86.543 58.060 39.917 124.582 69.924

(g/kg) AP 73.575 151.331 121.130 122.532 69.311 96.424 58.173 41.278 130.395 77.161

RT 74.413 271.566 123.320 116.248 69.942 123.676 59.261 62.567 183.689 77.565

Mn BP 3055.887 1009.020 1719.269 1130.169 1354.258 1523.595 2806.147 2510.745 3462.776 1927.364

(mg/kg) AP 3161.474 1086.162 1725.214 1139.184 1396.008 1524.008 2835.425 2513.377 3468.520 1933.290

RT 3195.745 1113.657 1733.166 1222.624 1462.462 1602.877 2886.338 2578.118 3501.004 1961.021


121

BP-Before Processing, AP- After Processing, RT-Retailer

As, Hg, and Cd were Below Detection Limit of 0.001 mg/kg

ELEMENT Ntonso Jamasi Aboaso Mampong-

ten

Nkwanta Fawode Ahwiaa Agona Pankro-

no

Asenua

K BP 258.753 364.533 586.473 1668.780 146.666 963.21 461.107 1271.550 585.740 854.537

(g/kg) AP 261.003 364.653 588.070 1669.640 146.667 963.90 461.250 1272.003 585.893 855.050

RT 261.470 364.677 590.120 1770.770 146.770 963.93 461.448 1272.020 585.973 856.020

Na BP 5512.350 6164.657 5109.217 4799.194 8219.754 6893.246 4062.321 5781.442 5705.513 4414.710

(mg/kg) AP 5515.215 6180.259 5111.987 4883.900 8265.603 6943.451 4076.024 5876.419 5806.572 4427.254

RT 5561.201 6185.411 5120.698 4893.684 8277.351 6947.125 4081.943 5879.316 5821.604 4437.164


122

Table B3: Results of the elemental composition in honey from the Greater Accra region


ELEMENT Ayimen-sa Akwetey-man Amasaman Pokuase Awoshie Weija Adenta Ableku-ma Oyibi Afienya

Co BP 0.037 0.036 0.046 0.035 0.017 0.036 0.042 0.036 0.041 0.037

(mg/kg) AP 0.037 0.037 0.050 0.035 0.020 0.036 0.042 0.036 0.041 0.060

RT 0.040 0.041 0.050 0.039 0.021 0.036 0.042 0.036 0.041 0.094

Pb BP 0.234 0.138 0.174 0.336 0.090 0.132 0.318 0.114 0.030 0.036

(mg/kg) AP 0.258 0.264 0.432 0.456 0.162 0.462 0.516 0.150 0.162 0.198

RT 0.558 0.486 0.498 0.660 0.336 0.473 0.576 0.186 0.504 0.288

Cr BP 0.040 0.036 0.039 0.046 0.040 0.047 0.036 0.042 0.042 0.048

(mg/kg) AP 0.042 0.038 0.042 0.047 0.041 0.049 0.040 0.042 0.048 0.057

RT 0.042 0.038 0.042 0.058 0.053 0.052 0.046 0.042 0.048 0.078

Fe BP 1.824 2.076 2.676 2.466 2.310 2.586 2.184 2.586 3.978 3.036

(mg/kg) AP 2.862 2.706 3.216 2.922 3.150 2.988 3.822 3.096 4.236 3.396

RT 3.654 3.408 11.052 2.994 3.786 3.126 4.104 3.444 4.536 7.572

Mg BP 92.191 300.125 229.918 316.258 76.895 122.319 179.214 145.003 75.697 239.265

(mg/kg) AP 92.218 316.214 229.920 323.451 79.888 132.214 192.905 145.214 81.832 241.817

RT 93.145 319.125 226.126 350.144 89.126 132.108 216.107 150.136 82.987 247.442

V BP 1.001 5.942 9.661 3.145 1.158 4.129 4.718 4.271 0.962 1.932

(mg/kg) AP 1.231 6.291 11.441 3.142 1.482 6.459 4.771 5.142 0.987 2.164

RT 1.426 8.241 17.215 3.026 1.692 6.618 6.135 12.152 3.219 9.215

Cu BP 150.246 30.451 249.113 4.524 21.672 77.217 288.298 63.456 11.924 55.123

(mg/kg) AP 150.339 30.442 254.692 5.241 24.135 79.114 264.221 68.986 14.245 64.932

RT 156.226 31.913 260.192 6.841 36.122 84.126 271.351 71.532 22.681 65.112

Al BP 212.137 501.284 224.248 372.365 60.159 192.697 89.741 75.667 100.254 99.125

(mg/kg) AP 218.258 503.624 241.363 373.692 66.661 197.265 85.214 77.326 103.935 100.412

RT 250.984 523.148 299.122 391.568 67.011 198.358 84.968 78.265 112.368 107.845

Ca BP 42.137 73.567 73.567 108.867 52.267 62.16 23.926 153.243 29.927 57.778

(g/kg) AP 43.237 75.716 73.927 109.463 53.827 63.216 24.978 154.573 42.130 57.913

RT 51.577 76.613 74.177 111.247 62.136 63.288 26.863 157.577 42.136 58.823

Mn BP 2514.121 803.155 2240.872 2484.151 1290.411 965.356 1125.349 1324.124 906.054 1357.754

(mg/kg) AP 2539.483 811.671 2246.246 2488.623 1298.245 967.994 1169.384 1377.717 906.154 1366.241

RT 2566.847 902.646 2297.568 2512.352 1301.254 977.012 1198.377 1445.668 907.264 1392.154

K BP 317.267 430.040 181.525 323.453 166.990 331.063 681.440 456.163 231.137 408.620

(g/kg) AP 317.450 430.090 181.544 323.463 167.070 333.157 681.460 456.247 231.143 408.590

RT 317.503 430.120 181.605 323.727 167.190 333.163 681.743 456.250 231.270 408.677

Na BP 5693.562 4185.411 3278.903 900.214 1262.638 1974.021 4662.016 2575.330 3154.232 4210.030

(mg/kg) AP 5704.148 4199.642 3283.439 911.132 1267.511 1976.327 4701.534 2585.024 3154.241 4216.250

RT 5784.012 4203.151 3361.189 926.415 1277.215 1991.900 4716.436 2587.100 3163.018 4219.295

BP-Before Processing, AP- After Processing, RT-Retailer (As, Hg, and Cd were Below Detection Limit of 0.001 mg/kg)


123

APPENDIX C

Table C1: P- Values calculated for the variations of the elements in the samples (Brong Ahafo Region)

BRONG AHAFO REGION

Element Atebubu Fiapre Drobo Dumasua Mantukwa Nsoatre Kintampo Techiman Tanoso Berekum

Co(mg/kg) P-

value P=0.125 P=1.000 P=1.000 P=1.000 P=1.000 P=0.729 P=0.000 P=0.037 P=0.000 P=0.125

Pb( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Cr( mg/kg) P-

value

P=0.000 P=0.729 P=0.438 P=0.000 P=0.000 P=0.068 P=0.000 P=0.000 P=0.016 P=0.191

Fe( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Mg( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

V(ppm) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Cu( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Al( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Ca (g/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Mn( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

K (g/kg) P-

value

P=0.000 P=0.001 P=0.108 P=0.002 P=0.000 P=0.000 P=0.034 P=0.000 P=0.000 P=0.000

Na( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000


124

Appendix C

Table C2: P- Values calculated for the variations of the elements in the samples (Ashanti Region)

ASHANTI REGION

Element Ntonso Jamasi Aboaso Mampo-

ngten

Nkwanta Fawode Ahwiaa Agona Pankrono Asenua

Co(mg/kg) P-


Pb( mg/kg) P-

value P=0.126

P=0.000

P=0.000

P=0.972

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Cr( mg/kg) P-

value P=0.729 P=0.242 P=0.824 P=0.000 P=0.729 P=0.000 P=0.068 P=0.003

Fe( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Mg( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

V(ppm) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.238 P=0.000 P=0.000 P=0.000 P=0.000

Cu( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.422 P=0.000

Al( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Ca (g/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Mn( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

K (g/kg) P-

value

P=0.000 P=0.051 P=0.000 P=0.000 P=0.162 P=0.000 P=0.002 P=0.000 P=0.002 P=0.000

Na( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000


125

Appendix C

Table C3: P- Values calculated for the variations of the elements in the samples (Greater Accra Region)


Element Ayimen-

sa

Akwete-

yman

Amasam-an Pokuase Awoshie Weija Adenta Ableku-

ma

Oyibi Afienya

Co(mg/kg) P-


Pb( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Cr( mg/kg) P-

value

P=0.047 P=0.047 P=0.047 P=0.000 P=0.000 P=0.317 P=0.317 P=1.000 P=0.000 P=0.000

Fe( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Mg( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

V(ppm) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Cu( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Al( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.021 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Ca (g/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

Mn( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000

K (g/kg) P-

value

P=0.001 P=0.410 P=0.111 P=0.002 P=0.317 P=0.000 P=0.001 P=0.244 P=0.050 P=0.167

Na( mg/kg) P-

value

P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000 P=0.000


126

APPENDIX D1

SAMPLE QUESTIONNAIRES

PERSONAL INFORMATION

GENDER: Male Female

AGE RANGE: 10– 20 years 21 – 30 years 31 – 40years 41 – 50 years

51 – 60 years 61– 70 years 71– 80 years 81– 90 years

LEVEL OF EDUCATION: basic secondary tertiary post graduate none

OCCUPATION:…………………...REGION……………DISTRICT………………….

Commercial bee keeping……..………………… Bee hunting………………………….

1) How long have you been in the honey business?

(a) 0-5 years

(b) 6-10 years

(c) 11-20 years

(d) 21-30 years

(e) Above 30 years

2) How many colonies do you have? (where applicable)

3) Which people do you normally sell your products to?

(a) Individuals

(b) Traders

(c) Both

(d) Others, e.g………………………………

4) What is the location of your honey farm (Apiaries)?

(a) Close to an industry

(b) Close to a tarred road/ filling station

(c) Few meters away from human settlement

(d) Other

5) What equipment do you usually use during honey extraction

(a) Wood

(b) Metal

(c) Both (wood and metal)

(d) others

6) What kind of safety equipment do you use/Measures taken to reduce contamination

(a) Gloves

(b) Goggles

(c) Head cover

(d) Others

7) Containers for keeping the products

(a) New plastic containers

(b) Used plastic containers


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(c) Metal containers

8) Treatment of Containers before honey storage

(a) Rinsing

(b) Thorough washing with soap or detergents

(c) No washingorrinsing

(d) others

9) What is the color of your honey?

(a) Brown

(b) Colourless

(c) Dark brown

(d) Other

10) Honey’s consistency?

(a) Fluid

(b) Viscous

(c) Partly to entirely crystallized

11) Aroma or flavor of the honey?

(a) Sweet scented

(b) Foul smell

(c) Fermented

(d) Other

12) What treatment method do you use after extraction?

(a) Filtering

(b) Removal of contaminants

(c) Heating

(d) Sieving

(e) Other

13) Do you add any additives before selling them?

(a) Yes

(b) No

14) If yes what is the additive?

15) (If yes), why do you add them?

(a) To improve the flavor

(b) To change the colour

(c) To increase the volume

(d) To change honey's consistency

(e) Others

16) Do you have particular days and times that you usually do the extraction?

(a) Yes

(b) No

17) (If yes), why?………………………………………

18) How are the bees deployed for pollination?

(a) On a small scale


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(b) On commercial basis.

(c) Others

19) What food do you normally feed the bee colonies on?

(a) Protein supplements

(b) Pollen supplements

(c) Others

20) What methods are employed for feeding such foods to the bee colonies?

(a) You collect pollen from flowers and bring back to the hive

(b) From nitrogenous food-stuffs provided by the beekeeper

(c) Others

21) How do you control Pest and disease, and the chemical employed?

(a) Use of oxytetracycline and fumagillin as aids in the control and prevention of

bee diseases

(b) Diagnosis and treatment of disease in the laboratory

(c) Others

22) Bees’ foraging activities and the size of the area normally covered.

(a) On a stand of honeysuckle in the farm

(b) Brightly colored flowers in the farm

(c) Other

23) Which place do you normally sell the honey?

(a) Hawking

(b) Market

(c) Home

(d) Roadside

(e) Schools

(f) Other


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APPENDIX D2

RESPONSE TO QUESTIONNAIRES

Concern Response

Frequency Percent

How old are you? 10-20years 1 3.3

21-30years 5 16.7

31-40years 1 3.3

41-50years 7 23.3

51-60years 7 23.3

51-60years 7 23.3

61-70years 8 26.7

81-90years 1 3.3

Total 30 100.0

How long have you been in

the Honey business? 0-5 years 4 13.3

6-10 years 9 30.0

11-20 years 11 36.7

21-30 years 3 10.0

more than 30 years 3 10.0

Total 30 100.0

Equipment used in honey’s

extraction wood 13 43.3

metal 3 10.0

both (wood and metal) 14 46.7

Total 30 100.0

Measures taken to reduce

contamination Gloves only 8 26.7


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Concern Response

Frequency Percent

Head cover only 3 10.0

head cover and gloves 17 56.7

other 2 6.7

Total 30 100.0

Containers for keeping or

storing honey New Plastic containers 6 20.0

Used plastic containers 18 60.0

Metal containers 6 20.0

Total 30 100.0

Treatment of containers prior

to storage Rinsing 19 63.3

Thorough washing with soap or

detergents 7 23.3

No washing or rinsing 4 13.3

Total 30 100.0

Treatment method do used

after extraction? Filtering 21 70.0

Heating 7 23.3

Other (sieving, decanting, hand

squeezing etc) 2 6.7

Total 30 100

Additives? yes 4 13.3

no 26 86.7

Total 30 100.0

Why add them? To increase volume 2 6.7


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Concern Response

Frequency Percent

To change honey's consistency 2 6.7

Total 4 13.3

System(missing) 26 86.7

Total 30 100.0

What additive? water 4 13.3

none 26 86.7

Total 30 100.0

Selling Place? hawking 8 26.7

market 7 23.3

home 4 13.3

roadside 7 23.3

schools 4 13.3

Total 30 100.0

Apiary’s location? Close to an industry 2 6.7

Close to a tarred road/ filling stations 8 26.7

Few meters away from human

settlement 16 53.3

others 4 13.3

Total 30 100.0


Monitoring of Elemental Composition of Honey from Selected ...

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