Research Article A Simple and Quick Method for the...

Research ArticleA Simple and Quick Method for the Determination of Pesticidesin Environmental Water by HF-LPME-GCMS

Helveacutecio C Menezes1 Breno P Paulo1 Maria Joseacute N Paiva2 and Zenilda L Cardeal1

1Departamento de Quımica ICEx Universidade Federal de Minas Gerais Avenida Antonio Carlos6627-31270901 Belo Horizonte MG Brazil2Universidade Federal de Sao Joao Del Rei Avenida Sebastiao Goncalves Coelho 400 Chanadour35501-296 Divinopolis MG Brazil

Correspondence should be addressed to Zenilda L Cardeal zenildacardealgmailcom

Received 10 May 2016 Revised 18 August 2016 Accepted 1 September 2016

Academic Editor Yolanda Moliner Martınez

Copyright copy 2016 Helvecio C Menezes et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

This paper describes a simple and quick method for sampling and also for carrying out the preconcentration of pesticides inenvironmental water matrices using two-phased hollow fiber liquid phase microextraction (HF-LPME) Factors such as extractionmode time solvents agitation and salt addition were investigated in order to validate the LPMEmethodThe following conditionswere selected 6 cm of polypropylene hollow fiber ethyl octanoate as an acceptor phase and extraction during 30min under stirringat 200 rpm The optimized method showed good linearity in the range of 014 to 20000120583g Lminus1 the determination coefficient (1198772)was in the range of 09807ndash09990TheLOD ranged from004 120583g Lminus1 to 044 120583g Lminus1 and LOQ ranged from014 120583g Lminus1 to 169 120583g Lminus1The recovery ranged from 8517 to 11473 The method was applied to the analyses of pesticides in three environmental watersamples (a spring and few streams) collected in a rural area from the state of Minas Gerais Brazil

1 Introduction

The extensive use of pesticides harms the soil [1ndash4] air [5 6]food [7ndash10] surface and ground waters [11ndash14] and qualitycausing serious impacts on the environment and on humanhealth In natural waters pesticide residues are present atvery low levels and can be degraded when submitted to lowerpH levels or exposed to solar radiation [15] Furthermore thecomplexity of environmental matrices and large variationsin physical and chemical properties of the target compoundsrequires the use of sensitive and selective techniques Severalanalytical techniques such as high-performance liquidchromatography (HPLC) [16 17] gas chromatography (GC)[18 19] micellar electrokinetic chromatography (MEKC)[20 21] enzyme-linked immunosorbent assays (ELISA)[22ndash24] and gas and liquid chromatography coupled tomass spectrometry (GCMS LC-MS) [25 26] have beenused for analyses of pesticides in different matrices Thechromatographic techniques combine separation capabilitieswith sensitivity from the mass systems such as ion trap (IT)

triple quadrupole (QqQ) and time of flight (TOF) Howeverthese techniques still remain as challenges related to lowdetection limits the variety of pesticides classes and samplepreparation The analytes extraction in chromatographicanalysis is critical to the methodrsquos performance since itenables the elimination of possible array interferences andthe preconcentration of analytes Traditional extractionmethods such as solid phase extraction (SPE) [27 28] andliquid-liquid extraction (LLE) are multistage consumingtoxic solvents and require a long time to execute Solidphase microextraction (SPME) [29ndash31] is a technique thatis based on the partition between the analyte present in thematrix and the fiber coating over a small fused silica rodThis technique is solvent-free and gathers in a single stepextraction and preconcentration However problems such aslow resistance short lifetime and high cost remain Recentlyseveral materials have been proposed to increase the strengthand durability of SPME coatings such as carbon materials[32] Hollow fiber liquid phase microextraction (HF-LPME) [33ndash37] and dispersive liquid-liquid microextraction

Hindawi Publishing CorporationJournal of Analytical Methods in ChemistryVolume 2016 Article ID 7058709 11 pageshttpdxdoiorg10115520167058709

2 Journal of Analytical Methods in Chemistry

(DLLME) [38 39] have been used for the concentration andclean-up step of pesticides analyses in waters HF-LPMEwas developed by Pedersen-Bjergaard and Rasmussen [40]and has been used by many researchers in recent years dueto its low cost which enables the rejection of the materialafter use eliminating problems of cross-contamination orlow reproducibility as well as its decreased consumptionof organic solvents Moreover the process is simple anda clean-up step is not necessary and can be applied to avariety of arrays reaching high enrichment factors [41] Thetechnique consists of a capillary porous hydrophilic fiberimpregnated with organic solvent and its interior filled withan acceptor phase so that it does not come into direct contactwith the matrices allowing for the application of agitationduring extraction [42] HF-LPME can be used in two or threephases With two phases the analyte is extracted from thedonor through an organic solvent immiscible in water thatfills the membrane pores passing to the acceptor stage whichcorresponds to the same solvent [43] With three phasesthe analyte is extracted from a donor phase through anorganic solvent immiscible in water for an aqueous solution(acceptor phase) inside the fiber The organic phase acts asa barrier preventing contact between the phases Despitethe extensive use of HF-LPME for extraction of pesticidesin water [33 44 45] the reported studies using GCMS aregenerally for just one pesticide class Therefore this studypresents the development of a simple and low-cost two-phaseHF-LPME methodology for multiresidue microextractionof organophosphorus phthalimides organochlorines andtriazoles pesticides from environmental water using GCMSThe pesticides selected were parathion-methyl (OO-dimeth-yl-O-p-nitrophenyl phosphorothioate) chlorpyrifos (OO-diethyl O-356-trichloro-2-pyridyl phosphorothioate) cap-tan (N-(trichloromethylthio)cyclohex-4-ene-12-dicarbox-imide) procymidone (N-(35-dichlorophenyl)-12-dimethyl-cyclopropane-12-dicarboximide) 120572-endosulfan (145677-hexachloro-8910-trinorborn-5-en-23-ylenebismethylenesulfite) prothiofos ((RS)-(O-24-dichlorophenyl O-ethylS-propyl phosphorodithioate)) cyproconazole ((2RS3RS2RS3SR)-2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-124-tri-azol-1-yl)butan-2-ol) ethion (OOO1015840O1015840-tetraethyl SS1015840-methylene bis(phosphorodithioate)) triazophos (OO-dieth-yl O-1-phenyl-1H-124-triazol-3-yl phosphorothioate) andphosmet (OO-dimethyl S-phthalimidomethyl phosphorod-ithioate) The main parameters affecting the extractionefficiency were optimized using GCMS determination Theprocedure presented good accuracy and precision and lowlimits of quantification and detection besides good recovery

2 Materials and Methods

21 Chemical andMaterials Parathion-methyl chlorpyrifoscaptan procymidone 120572-endosulfan prothiofos cyprocona-zole ethion triazophos and phosmet of 98ww puritygrade were purchased from Sigma-Aldrich (St Louis MOUSA) The choice of pesticides was based on their useon the region of samples collection A work solution of2000mg Lminus1 was prepared by the appropriate dilution inHPLC-grade methanol Sigma-Aldrich (St Louis Missouri

United States) This work solution was used for the matrixspike in different concentration levels (500 to 16000 120583g Lminus1)to optimize the extraction conditions during the validationstudy Calibration standards were prepared at 500 10002000 4000 8000 and 16000 120583g Lminus1 concentrations usingultrapure water produced in a Purelab UVMK2 purifier fromElga (Marlow Buckinghamshire England) 1-Octanol HPLCgrade was purchased from Sigma-Aldrich (St Louis Mis-souri United States) ethyl decanoate acetonitrile and ethyloctanoate were purchased from J T Baker (Xalostoc EdoMEXMexico) Hollow fiber was purchased fromUnderlyingPerformance Co (Wuppertal Germany)

22 Instrumentation for GCMS The analysis was carriedout with a Shimadzu (Kyoto Japan) GCMS system modelGC-2010QP-2010 high-performance quadrupole The massspectrometer operated within the electron impact mode (EI)at 70 eV A capillary column (30m times 025mm times 025 120583m)containing 5 diphenyl and 95 dimethylpolysiloxane HP-5MS from Agilent Technology Inc (Santa Clara CaliforniaUnited States) was used The oven temperature programbegan at 80∘C and raised to 200∘C at a rate of 8∘Cminminus1up to 300∘C at 30∘Cminminus1 and held there for 3min Helium(99999) was the carrier gas at a flow rate of 10mLminminus1The injector was operated at 280∘C in splitless mode for3min followed by a 1 20 split ratio (RD) The ion sourcetemperature was 200∘C and the GCMS interface tempera-ture was 300∘C The analysis was carried out in the selectedionmonitoring (SIM)modeThe quantification was achievedusing the ion fragments shown in Table 2 The collectionof raw data was carried out using a LabSolution softwareShimadzu (Kyoto Japan)

23 HF-LPME Extraction Procedure Aqueous standards ofpesticides were prepared by spiking an appropriate amountof the working standard The extraction and desorptionconditions were based on Psillakis and Kalogerakisrsquos study[49] LPME sampling was tested in two and three phasesstudy of salt addition stirring speed and extraction timeThe extractions were carried out with propylene hollowfiber of 60 cm length 600 120583m of internal diameter andwall thickness of 200120583m Before the extraction the hollowfiber was filled with 300 120583L of solvent using a microsyringeThen the U-shaped solvent-filled fiber was connected totwo syringe needles and immersed into the vial containing1500mL of aqueous donor solutions spiked with 1000 120583g Lminus1of standard pesticides solutions for the extraction undermagnetic stirring After the extraction the acceptor phasewas removed with a microsyringe and transferred to a 20mLvial to the injection of 10 120583L in GCMS All experiments wereperformed in replicates (119899 = 3)

24 Samples Collection Real samples of surface water werecollected in a rural area of the state of Minas Gerais BrazilIn this region the main crops are coffee eucalyptus andtomatoes Samples of surface water were sampled 2 kmdown-stream of these crops The collected samples showed clearappearance and no suspended particles The amber-glass

Journal of Analytical Methods in Chemistry 3

collection bottles were previously washed with a solutionof 50 vv alkaline detergent under ultrasound bath for15 minutes and rinsed with ultrapure water Water samplescollected with these bottles were carefully filled to the brimto avoid trapping air After filling the bottles they were sealedwith Teflon lined screw caps kept in ice and transported tothe laboratory before 24 h where they were stored at 4∘C untilthe extraction and analysis

25 Quality Control and Quality Assurance The qualitycontrol and the quality assurance method were carried outaccording to EURACHEM guidelines [50] The limits ofdetection (LOD) and limits of quantification (LOQ)were cal-culated from mean and standard deviation of 10 blank mea-surements with 95 confidence Linearity was established forall the analytes (from 004 to 1500 120583g Lminus1) Six concentra-tion levels were analyzed with three measurements at eachconcentration level The Hartley test using Origin 80 fromOriginLab Co software (Northampton MA United States)was used to verify the instrumental response homogeneity ofvariances The result of this test indicated heteroscedasticityof variances so the linear models for the calibration curveswere constructed by the least squaresmethodweighted by theexperimental variance Intraday repeatability was calculatedwith four replicates Recovery was evaluated using blanksample water spiked with 100 120583g Lminus1

3 Results and Discussion

31 Optimization of HF-LPME Method The most importantfactors related to the HF-LPME extraction method such asthe extraction mode solvents agitation salt addition andextraction time were optimized before the validation testsThe pesticides studied were chosen based on the informationof their broad use (higher quantity retailed) in the culturesof the region where the samples were collected Table 1shows few relevant physicochemical properties of the selectedpesticides [51]

311 Extraction Mode and Solvents The extraction modewith three phases was evaluated using acetonitrile asthe acceptor phase 1-octanol ethyl decanoate and ethyloctanoatewere tested as the organic phase Aqueous solutionsspiked with standard pesticides were used as donor solutions

A significant loss of the organic phase during the three-phased extraction process significantly affected the recoveryof the acceptor phase for further analysis Subsequentlythe two-phase mode was tested using 1-octanol or ethyldecanoate and ethyl octanoate as the acceptor phase andthe aqueous solutions spiked with standard pesticides asdonor solutions The two-phase extraction method providedsignificant improvement in the recovery due to good immo-bilization of the acceptor phase in the fiber Ethyl octanoatewas selected as the acceptor phase due to its superior responseto most pesticides as shown in Figure 1

The results obtained with 1-octanol were relatively lowercompared to the other acceptor phases studied This can beexplained by the difference in polarity between them since

Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

Pesticides

Ethyl decanoateEthyl octanoate

times107

00

02

04

06

08

10

12

Peak

area

1-Octanol

Figure 1 Effect of organic solvent on pesticidersquos extraction effi-ciency Conditions of the donor phase 15mL of water spiked at100 120583g Lminus1 of each pesticide extraction time of 60min and stirringspeed of 100 rpm Error bars represented the standard deviation ofthe mean peak area for 119899 = 3 replicates

ethyl decanoate and ethyl octanoate are less polar than 1-octanol Therefore the studied analytes are best extractedin more hydrophobic solvents because all 119870ow values aregreater than 1 This indicates that there is greater solubilityin nonpolar solvent increasing the distribution ratio betweenthe organic acceptor solution and the donor solution [52]The different areas observed for organochlorine pesticidesin relation to organophosphorus areas are mainly due to thefact that the electron impact mode used in MS detector showextensive fragmentation Electron impact produces relativelylow signal intensity with poor sensitivity for organochlorinescompounds [53]

312 Agitation Agitation provides continuous exposure ofthe extraction surface for the aqueous sample The fiber isdepleted of the analytes due to their partitioning in the donorphase hence the agitation diminishes this depletion area bybringing fresh undepleted sample close to the fiber Agitationalso reduces the time required to reach thermodynamicequilibrium and induces convection in the membrane phaseTo optimize sample agitation ethyl octanoate was used as theacceptor phase and aqueous pesticide was used as the donorphase The stirring rates studied were 0 200 400 800 and1600 rpm using metallic stir bars of 05 cm The extractiontime was 60min The results presented in Figure 2 show thatthe largest areas were obtained using 200 rpm of agitationspeed It was also observed that the agitation speed higher


Table1Ph

ysicochemicalprop

ertie

softhe

selected

pesticides

Pesticide

CASnu

mber

Chem

icalcla

ssMolecular

form

ula

Structuralform

ula

log119870

owWater

solubility(m

gLminus1

)

Triazoph

os24017-47-8

Organop

hospho

rus

C 12

H16

N3

O3

PSN

NN

OOO P

S

CH

3

CH

3

334

3500

Prothiofos

34643-46

-4Organop

hospho

rus

C 11

H15

Cl2

O2

PS2

Cl

ClSS P

O

O567

007

Chlorpyrifo

s2921-88-2

Organop

hospho

rus

C 9H11

Cl3

NO3

PSN

OO

OPS

ClCl

Cl470

105

Parathion-methyl

298-00-0

Organop

hospho

rus

C 8H10

NO5

PSO

OO O

PS

N+ O

minus

286

377

Captan

133-06-2

Dicarbo

ximide

C 9H8

Cl3

NO2

S

ClCl Cl

SNO O

250

520

Cyprocon

azole

94361-0

6-5

Triazole

C 15

H18

ClN3

O

Cl

HO

NN

N

309

9300


Table1Con

tinued

Pesticide

CASnu

mber

Chem

icalcla

ssMolecular

form

ula

Structuralform

ula

log119870

owWater

solubility(m

gLminus1

)

Ethion

563-12-2

Organop

hospho

rus

C 9H22

O4

P 2S 4

OO

OO

PP

SS

SS

507

200

Procym

idon

e32809-16-8

Dicarbo

ximide

C 13

H11

Cl2

NO2

Cl

Cl

O

ON

330

246

120572-End

osulfan

115-29-7

Organochloride

C 9H6

Cl6

O3

SOO

O

Cl

ClCl

Cl

Cl

Cl

H H

S475

032

Phosmet

732-11-6

Organop

hospho

rus

C 11

H12

NO4

PS2

NO

OOO

PS

S296

1520


Table 2 Analytical performance of GCMS method using HF-LPME for the extraction of pesticides in environmental wateraPesticide Quantification ion (m zminus1) Linearity (1198772) bPrecision RSD () cRecovery () LOD (120583g Lminus1) LOQ (120583g Lminus1)Parathion-methyl 263 09932 280 11005 004 014Chlorpyrifos 97 09950 398 11473 044 146Captan 79 09955 1498 10065 020 067Procymidone 67 09996 477 11368 017 057120572-Endosulfan 195 09903 650 11075 012 169Prothiofos 113 09990 090 11217 035 116Cyproconazole 125 09943 931 8517 014 048Ethion 125 09807 236 11336 013 042Triazophos 161 09906 1356 9108 009 031Phosmet 160 09874 1516 11110 023 076aCompounds are listed in sequence of elution bcConcentration 10 120583g Lminus1 119899 = 3

Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

0 rpm200 rpm400 rpm

800 rpm1600 rpm

times106

0

1

2

3

4

5

6

7

Peak

area

Figure 2 Effect of the stirring speeds on pesticide extractionefficiency Extraction conditions of the donor phase 150mL ofwater spiked at 1000 120583g Lminus1 of each pesticide extraction time of60min and ethyl octanoate in the acceptor phase Error barsrepresented the standard deviation of the mean peak area for 119899 = 3replicates

than 200 rpm decreases extraction efficiency despite the factthat stirring promotes mass transfer between the donor andacceptor phases The relative decreased extraction yield wasdue to the fact that vigorous agitation promotes the formationof air bubbles which adhere to the fiber surface [54] Theefficiency of the extraction at 0 rpm and 400 rpm are similarbecause in the static stage the diffusion layer close to the fiberis not renewed this effect decreases the mass transfer to thedonor layer However the formation of bubbles on the outersurface of the fiber starts from 400 rpm which contribute toreducing the mass transfer of the acceptor phase

313 The Salting-Out Effect The effect of salt addition tothe LPME extraction of the pesticides was examined in thepresence of different concentrations of NaCl 00 50 100and 150wv The extraction time was 60min The acceptorphase was ethyl octanoate with agitation at 200 rpm Theaddition of salt in the aqueous samples generally improves theextraction of analytes in the organic phase The salt increasesthe ionic strength decreasing the solubility of hydrophobicanalytes in the donor phase therefore it enhances theirpartitioning into the acceptor phase However in this studythe addition of salt did not present a positive influence onthe extraction process of most analytes (Figure 3) Phosmetpresented a large improvement in the extraction efficiency of50 NaCl concentration although at higher concentrationsthe peak area decreased drastically The presence of higherconcentrations of salt can change the physical properties ofthe extraction film reducing the diffusion rates of the analytesinto the organic phase [55] Therefore the increase in ionicstrength resulting from the addition of salt increased thesalting-in effectThis effect has been observed in other studiesregarding environmental water samples [35 56]

314 Extraction Time LPME sampling is an equilibriumprocess in which analytes are partitioned between the donorphase and acceptor phase The equilibrium time refers to thetime after which the amount of extracted analyte remainsconstant Extraction times of 100 200 300 400 and600 minutes were tested for the extraction using the bestconditions of the variables previously assessed As seen inFigure 4 the extraction efficiency reached its maximumvalue after 30min for most of the pesticides evaluatedTherefore this was the extraction time selected Periods above30min reduced extraction efficiency in some analytes suchas parathion-methyl captan phosmet and triazophos Thisreduction occurs due to the prolonging of the stirring timewhich originates the formation of bubbles in the outer fibercontributing to increased losses of the donor phase

32 Chromatographic Evaluation After evaluating the differ-ent parameters that could affect the extraction the followingoptimized conditions were selected for all experiments 6 cmpolypropylene hollow fiber impregnated and filled with 30 120583L


Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

NaCl 00 wvNaCl 50 wv


times106

0

1

2

3

Peak

area

Figure 3 Influence of the aqueous phase ionicrsquos strength onpesticides extraction efficiency Extraction conditions of the donorphase 150mL of water spiked at 1000 120583g Lminus1 of each pesticide withNaCl extraction time of 60min stirring speed of 100 rpm and ethyloctanoate in the acceptor phase Error bars represented the standarddeviation of the mean peak area for 119899 = 3 replicates

Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

times106

00

05

10

15

20

25

30

35

Peak

area

10 min20 min30 min

40 min60 min

Figure 4 Effect exposure times on the extraction efficiency Extrac-tion conditions of the donor phase 150mL of water spiked at1000 120583g Lminus1 of each pesticide stirring speed of 200 rpm and ethyloctanoate in the acceptor phase Error bars represented the standarddeviation of the mean peak area for 119899 = 3 replicates

1

0

25

50

75

100

Inte

nsity

10

987

654

3

2

150125 175 200 225 250100

Time (min)

(a)

0

25

50

75

100

Inte

nsity

95

1

125 150 175 200 225 250100

Time (min)

(b)

Figure 5 (a) Chromatogram of pesticides GCMS analysis usingHF-LPME extraction Extraction for 30 minutes in aqueous donorsolution spiked at 500 120583g Lminus1 stirring speed 200 rpm and ethyloctanoate as acceptor phase 1 parathion-methyl 2 chlorpyrifos3 captan 4 procymidone 5 120572-endosulfan 6 prothiofos 7 cypro-conazole 8 ethion 9 triazophos 10 phosmet (b) Chromatogramof pesticides in real environmental water sample under sameextraction conditions

of ethyl octanoate immersion in a vial containing 150mL ofsample for 30min under stirring at 200 rpm and injection of10 120583L to the acceptor phase in the GCMS system Figure 5shows chromatogram of pesticides GCMS analysis usingHF-LPME extraction in aqueous donor solution spiked at500 120583g Lminus1 with standards (Figure 5(a)) and real environ-mental water sample (Figure 5(b)) under the same extractionconditions Chromatographic separation was satisfactory forall target analytes in a short time

Under the optimal extraction conditions ten pesticideswere selected for the analysisThe parameters linearity limitsof detection (LOD) limits of quantification (LOQ) recoveryand precision were carefully investigated The experimentalresults are presented in Table 2

A linear range of 014 120583g Lminus1 to 20000120583g Lminus1 was usedin the investigation The linearity was assessed by the deter-mination coefficient (1198772) that was in the range of 09807ndash09990The LOD ranged from 004120583g Lminus1 to 044 120583g Lminus1 andLOQ ranged from 014120583g Lminus1 to 169 120583g Lminus1 The recoveryand precision studies were performed by three replicates ofreal water samples spiked with concentration of 100120583g Lminus1of each pesticide Recovery ranged from 8517 to 11473Intraday precision (RSD 119899 = 3) ranged from 090 to1516Themerit parameters values of linearity and precisionobtained in this study are consistent with other resultsreported in the analysis of pesticides in water [37 57ndash61]On the contrary the limits of detection and quantificationobtained in this study were better than those obtained in


Table 3 Comparative study for some parameters of HF-LPME-GCMS developed method with other related methods

Extractionmethod

Number ofanalytes Multiclassa LOD (120583g Lminus1) Precision () Recovery () Extraction time (min) Cost effective Refer

SPE 12 Yes 0004ndash008 25ndash174 83ndash126 minus High [28]SPME 5 No 20ndash80 minus minus 30 High [31]HF-LPME 9 No 0002ndash0012 42ndash184 694ndash1227 360 Low [35]DLLME 18 No 0001ndash0025 5ndash15 75ndash101 05 Low [39]HF-LPMEb 3 No 0015ndash0080 87ndash30 Low [44]SPME 6 Yes 0003ndash0145 4ndash12 60 High [46]SPME 16 Yes 0015ndash013 19ndash96 82ndash114 60 High [29]SPME 7 Yes 0006ndash0600 27ndash235 60ndash121 80 High [47]SPME 16 Yes 002ndash030 63ndash169 702ndash1046 30 High [48]HF-LPME 11 Yes 004ndash035 09ndash152 852ndash1147 30 Low This workaPresence of different class of pesticides bSample extraction of 72 h

Table 4 Analyses of pesticides in real environmental water samples (spring water stream 1 and stream 2)

Pesticide Average (119899 = 3) concentrations (120583g Lminus1) cPermitted value (120583g Lminus1)Spring water Stream 1 Stream 2

Parathion-methyl a006 a008 015 35Chlorpyrifos bND ND ND dxCaptan ND ND ND xProcymidone ND ND ND x120572-Endosulfan a016 ND a020 02Prothiofos ND ND ND xCyproconazole ND ND ND xEthion a030 a031 ND xTriazophos a017 a014 a016 xPhosmet ND ND ND xaBelow LOQ bND not detected cRegulation 3572005 Ministry of Environment pesticide levels in surface water in Brazil dx not regulated by Brazilianlegislation

other works using HF-LPME [59 62] Besides comparingother methods described in the literature (Table 3) to themulticlass pesticides analysis thisHF-LPMEmethod presentsbetter precision and low cost

33 Analysis of Real Environmental Samples The applicationof the HF-LPME-GCMS method for determination of pes-ticides of real samples was achieved through the analysis ofthree real samples of surface water (spring stream 1 andstream 2) collected in a rural area of the state ofMinas GeraisBrazil

Agriculture is the main activity in the region upstreamThe concentrations determination for each pesticide in watersamples are shown in Table 4

Parathion-methyl was quantified in the sample of stream2 and detected in spring water and stream 1 The value foundfor this pesticide in the samples analyzed is lower than thelimit established by Brazilian legislation [63] Triazophoswas detected in all the samples analyzed 120572-Endosulfan wasdetected in the spring water and stream 2 Ethion wasdetected in spring water and stream 1 These results showthe ability of the method for the analysis of ten pesticides ofdifferent chemical classes in real samples

4 Conclusions

This study describes the use of a simple and quick methodfor the determination of pesticides in environmental waterby two-phase HF-LPME-GCMSThemain factors related toHF-LPME extraction method such as the extraction modesolvents agitation salt addition and extraction time wereinvestigated and optimized before the validation tests Theproposed method showed good linearity low detection andquantification limits high selectivity and good repeatabilityfor the pesticides selectedThis procedure is selective simplefast and low cost it has minimal use of solvents and doesnot require pretreatment of samples The results obtainedfrom the analyses of three environmental water samples(spring and streams) have demonstrated the ability of themethod to measure trace levels of pesticides This methodhas the potential for automation and capacity for integratedsampling

Competing Interests

The authors declare no conflict of interests


Acknowledgments

Funding for this study was provided by the Fundacao deAmparo a Pesquisa de Minas Gerais (FAPEMIG) and Con-selho Nacional de Desenvolvimento Cientıfico e Tecnologico(CNPq) The authors Helvecio Costa Menezes and Zenildade Lourdes Cardeal are beneficiaries of financial assistancefrom Coordenacao de Aperfeicoamento de Pessoal de NıvelSuperior (CAPES) Brazil

References

[1] D Fernandez-Calvino J A Rodrıguez-Suarez E Lopez-Periago M Arias-Estevez and J Simal-Gandara ldquoCoppercontent of soils and river sediments in a winegrowing areaand its distribution among soil or sediment componentsrdquoGeoderma vol 145 no 1-2 pp 91ndash97 2008

[2] M Pateiro-Moure C Perez-Novo M Arias-Estevez R Rial-Otero and J Simal-Gandara ldquoEffect of organic matter andiron oxides on quaternary herbicide sorption-desorption invineyard-devoted soilsrdquo Journal of Colloid and Interface Sciencevol 333 no 2 pp 431ndash438 2009

[3] E Pose-Juan R Rial-Otero M Paradelo J Simal-GandaraM Arias and J E Lopez-Periago ldquoBehaviour of metalaxylas copper oxychloride-metalaxyl commercial formulation vstechnical grade-metalaxyl in vineyards-devoted soilsrdquo Journalof Hazardous Materials vol 174 no 1ndash3 pp 181ndash187 2010

[4] M Pateiro-Moure M Arias-Estevez and J Simal-GandaraldquoCritical review on the environmental fate of quaternary ammo-nium herbicides in soils devoted to vineyardsrdquo EnvironmentalScience and Technology vol 47 no 10 pp 4984ndash4998 2013

[5] M Kosikowska andM Biziuk ldquoReview of the determination ofpesticide residues in ambient airrdquo TrACmdashTrends in AnalyticalChemistry vol 29 no 9 pp 1064ndash1072 2010

[6] V Yusa C Coscolla and M Millet ldquoNew screening approachfor risk assessment of pesticides in ambient airrdquo AtmosphericEnvironment vol 96 pp 322ndash330 2014

[7] R M Gonzalez-Rodrıguez R Rial-Otero B Cancho-Grandeand J Simal-Gandara ldquoOccurrence of fungicide and insecticideresidues in trade samples of leafy vegetablesrdquo Food Chemistryvol 107 no 3 pp 1342ndash1347 2008

[8] R M Gonzalez-Rodrıguez R Rial-Otero B Cancho-GrandeC Gonzalez-Barreiro and J Simal-Gandara ldquoA review onthe fate of pesticides during the processes within the food-production Chainrdquo Critical Reviews in Food Science and Nutri-tion vol 51 no 2 pp 99ndash114 2011

[9] O Lopez-Fernandez R Rial-Otero C Gonzalez-Barreiro andJ Simal-Gandara ldquoSurveillance of fungicidal dithiocarbamateresidues in fruits and vegetablesrdquo Food Chemistry vol 134 no1 pp 366ndash374 2012

[10] R Fernandez-Gonzalez I Yebra-Pimentel E Martınez-Carballo J Regueiro and J Simal-Gandara ldquoInputs ofpolychlorinated biphenyl residues in animal feedsrdquo FoodChemistry vol 140 no 1-2 pp 296ndash304 2013

[11] R P Schwarzenbach T Egli T B Hofstetter U von Guntenand B Wehrli ldquoGlobal water pollution and human healthrdquoAnnual Review of Environment and Resources vol 35 pp 109ndash136 2010

[12] A Bermudez-Couso D Fernandez-Calvino M A Alvarez-Enjo J Simal-Gandara J C Novoa-Munoz and M Arias-Estevez ldquoPollution of surface waters by metalaxyl and nitrate

from non-point sourcesrdquo Science of the Total Environment vol461-462 pp 282ndash289 2013

[13] A Pal Y L He M Jekel M Reinhard and K Y-H GinldquoEmerging contaminants of public health significance as waterquality indicator compounds in the urbanwater cyclerdquoEnviron-ment International vol 71 pp 46ndash62 2014

[14] S Z Lari N A Khan K N Gandhi T S Meshram and NP Thacker ldquoComparison of pesticide residues in surface waterand ground water of agriculture intensive areasrdquo Journal ofEnvironmental Health Science and Engineering vol 12 article 112014

[15] A G Souza L M Costa R Augusti and Z L CardealldquoDegradation of prototype pesticides submitted to conventionalwater treatment conditions the influence of major parametersrdquoWater Air and Soil Pollution vol 211 no 1ndash4 pp 427ndash434 2010

[16] K Jinno T Muramatsu Y Saito Y Kiso S Magdic andJ Pawliszyn ldquoAnalysis of pesticides in environmental watersamples by solid-phase micro-extractionmdashhigh-performanceliquid chromatographyrdquo Journal of Chromatography A vol 754no 1-2 pp 137ndash144 1996

[17] A Masia Y Moliner-Martinez M Munoz-Ortuno Y Picoand P Campıns-Falco ldquoMultiresidue analysis of organic pollu-tants by in-tube solid phase microextraction coupled to ultra-high performance liquid chromatography-electrospray-tandemmass spectrometryrdquo Journal of Chromatography A vol 1306 pp1ndash11 2013

[18] R M Toledano J M Cortes J C Andini J Villenand A Vazquez ldquoLarge volume injection of water in gaschromatographyndashmass spectrometry using the Through OvenTransfer Adsorption Desorption interface application to mul-tiresidue analysis of pesticidesrdquo Journal of Chromatography Avol 1217 no 28 pp 4738ndash4742 2010

[19] C Goncalves and M F Alpendurada ldquoSolid-phase micro-extraction-gas chromatography-(tandem) mass spectrometryas a tool for pesticide residue analysis in water samples athigh sensitivity and selectivity with confirmation capabilitiesrdquoJournal of Chromatography A vol 1026 no 1-2 pp 239ndash2502004

[20] R Carabias Martınez E Rodrıguez Gonzalo A I MunozDomınguez J Domınguez Alvarez and J Hernandez MendezldquoDetermination of triazine herbicides in water by micellarelectrokinetic capillary chromatographyrdquo Journal of Chromatog-raphy A vol 733 no 1-2 pp 349ndash360 1996

[21] P Soisungnoen R Burakham and S Srijaranai ldquoDetermina-tion of organophosphorus pesticides using dispersive liquid-liquidmicroextraction combinedwith reversed electrode polar-ity stacking modemdashmicellar electrokinetic chromatographyrdquoTalanta vol 98 pp 62ndash68 2012

[22] G Qian L Wang Y Wu et al ldquoA monoclonal antibody-basedsensitive enzyme-linked immunosorbent assay (ELISA) forthe analysis of the organophosphorous pesticides chlorpyrifos-methyl in real samplesrdquo Food Chemistry vol 117 no 2 pp 364ndash370 2009

[23] G Giraudi I Rosso C Baggiani C Giovannoli A Vanni andG Grassi ldquoDevelopment of an enzyme-linked immunosorbentassay for benalaxyl and its application to the analysis of waterand winerdquo Analytica Chimica Acta vol 392 no 1 pp 85ndash941999

[24] H Zhang SWang andG Fang ldquoApplications and recent devel-opments of multi-analyte simultaneous analysis by enzyme-linked immunosorbent assaysrdquo Journal of Immunological Meth-ods vol 368 no 1-2 pp 1ndash23 2011


[25] T Reemtsma L Alder andU Banasiak ldquoAmultimethod for thedetermination of 150 pesticide metabolites in surface water andgroundwater using direct injection liquid chromatographyndashmass spectrometryrdquo Journal of Chromatography A vol 1271 pp95ndash104 2013

[26] A Masia M Ibanez C Blasco J V Sancho Y Pico and FHernandez ldquoCombined use of liquid chromatography triplequadrupole mass spectrometry and liquid chromatographyquadrupole time-of-flight mass spectrometry in systematicscreening of pesticides and other contaminants in water sam-plesrdquo Analytica Chimica Acta vol 761 pp 117ndash127 2013

[27] M Vukcevic A Kalijadis M Radisic et al ldquoApplicationof carbonized hemp fibers as a new solid-phase extractionsorbent for analysis of pesticides in water samplesrdquo ChemicalEngineering Journal vol 211-212 pp 224ndash232 2012

[28] J L M Vidal M C P Espada A G Frenich and F JArrebola ldquoPesticide trace analysis using solid-phase extractionand gas chromatography with electron-capture and tandemmass spectrometric detection in water samplesrdquo Journal ofChromatography A vol 867 no 1-2 pp 235ndash245 2000

[29] M Tankiewicz C Morrison and M Biziuk ldquoMulti-residuemethod for the determination of 16 recently used pesticidesfrom various chemical groups in aqueous samples by using DI-SPME coupled with GCndashMSrdquo Talanta vol 107 pp 1ndash10 2013

[30] C Dong Z Zeng andM Yang ldquoDetermination of organochlo-rine pesticides and their derivations in water after HS-SPME using polymethylphenylvinylsiloxane-coated fiber byGC-ECDrdquoWater Research vol 39 no 17 pp 4204ndash4210 2005

[31] B A Tomkins and R H Ilgner ldquoDetermination of atrazine andfour organophosphorus pesticides in ground water using solidphase microextraction (SPME) followed by gas chromatogra-phy with selected-ion monitoringrdquo Journal of ChromatographyA vol 972 no 2 pp 183ndash194 2002

[32] F Ghaemi A Amiri and R Yunus ldquoMethods for coating solid-phase microextraction fibers with carbon nanotubesrdquo TrACmdashTrends in Analytical Chemistry vol 59 pp 133ndash143 2014

[33] M I Pinto G Sontag R J Bernardino and J P NoronhaldquoPesticides in water and the performance of the liquid-phasemicroextraction based techniques A reviewrdquo MicrochemicalJournal vol 96 no 2 pp 225ndash237 2010

[34] X Sun F Zhu J Xi et al ldquoHollow fiber liquid-phase microex-traction as clean-up step for the determination of organophos-phorus pesticides residues in fish tissue by gas chromatographycoupledwithmass spectrometryrdquoMarine Pollution Bulletin vol63 no 5ndash12 pp 102ndash107 2011

[35] I San Roman M L Alonso L Bartolome and R M AlonsoldquoHollow fibre-based liquid-phase microextraction techniquecombined with gas chromatography-mass spectrometry for thedetermination of pyrethroid insecticides in water samplesrdquoTalanta vol 100 pp 246ndash253 2012

[36] M Tankiewicz J Fenik and M Biziuk ldquoSolventless andsolvent-minimized sample preparation techniques for deter-mining currently used pesticides in water samples a reviewrdquoTalanta vol 86 no 1 pp 8ndash22 2011

[37] S-P Huang and S-D Huang ldquoDetermination of organochlo-rine pesticides in water using solvent cooling assisted dynamichollow-fiber-supported headspace liquid-phase microextrac-tionrdquo Journal of Chromatography A vol 1176 no 1-2 pp 19ndash252007

[38] K Seebunrueng Y Santaladchaiyakit and S SrijaranaildquoVortex-assisted low density solvent based demulsified dis-persive liquidndashliquid microextraction and high-performance

liquid chromatography for the determination of organophos-phorus pesticides in water samplesrdquo Chemosphere vol 103 pp51ndash58 2014

[39] C Cortada L Vidal R Pastor N Santiago and A CanalsldquoDetermination of organochlorine pesticides in water samplesby dispersive liquid-liquid microextraction coupled to gaschromatography-mass spectrometryrdquo Analytica Chimica Actavol 649 no 2 pp 218ndash221 2009

[40] S Pedersen-Bjergaard and K E Rasmussen ldquoLiquid-phasemicroextraction with porous hollow fibers a miniaturized andhighly flexible format for liquid-liquid extractionrdquo Journal ofChromatography A vol 1184 no 1-2 pp 132ndash142 2008

[41] M R Payan M A B Lopez R Fernandez-Torres M CMochon and J L G Ariza ldquoApplication of hollow fiber-basedliquid-phase microextraction (HF-LPME) for the determina-tion of acidic pharmaceuticals in wastewatersrdquo Talanta vol 82no 2 pp 854ndash858 2010

[42] S Pedersen-Bjergaard and K E Rasmussen ldquoLiquid-liquid-liquid microextraction for sample preparation of biologicalfluids prior to capillary electrophoresisrdquo Analytical Chemistryvol 71 no 14 pp 2650ndash2656 1999

[43] E Psillakis and N Kalogerakis ldquoDevelopments in liquid-phasemicroextractionrdquo TrACmdashTrends in Analytical Chemistry vol22 no 9 pp 565ndash574 2003

[44] T Berhanu NMegersa T Solomon and J A Jonsson ldquoA novelequilibrium extraction technique employing hollow fibre liquidphase microextraction for trace enrichment of freely dissolvedorganophosphorus pesticides in environmental watersrdquo Inter-national Journal of Environmental Analytical Chemistry vol 88no 13 pp 933ndash945 2008

[45] J Lee H K Lee K E Rasmussen and S Pedersen-BjergaardldquoEnvironmental and bioanalytical applications of hollow fibermembrane liquid-phase microextraction a reviewrdquo AnalyticaChimica Acta vol 624 no 2 pp 253ndash268 2008

[46] A Pereira E Silva and M J Cerejeira ldquoApplicability of thenew 60 120583m polyethylene glycol solid-phase microextractionfiber assembly for the simultaneous analysis of six pesticidesin waterrdquo Journal of Chromatographic Science vol 52 no 5 pp423ndash428 2014

[47] J S Merib V Simao A N Dias and E Carasek ldquoSimultaneousdetermination of trihalomethanes and organochlorine pesti-cides in water samples by direct immersion-headspace-solidphase microextractionrdquo Journal of Chromatography A vol 1321pp 30ndash37 2013

[48] A M Filho F N dos Santos and P A D P PereiraldquoDevelopment validation and application of a method basedon DI-SPME and GC-MS for determination of pesticides ofdifferent chemical groups in surface and groundwater samplesrdquoMicrochemical Journal vol 96 no 1 pp 139ndash145 2010

[49] E Psillakis and N Kalogerakis ldquoHollow-fibre liquid-phasemicroextraction of phthalate esters from waterrdquo Journal ofChromatography A vol 999 no 1-2 pp 145ndash153 2003

[50] EURACHEM The Fitness for Purpose of Analytical MethodsA Laboratory Guide to Method Validation and Related TopicsLGC Teddington UK 1st edition 1998

[51] IUPAC global availability of information on agrochemicalshttpsitemhertsacukaeruiupacindexhtm

[52] K E Rasmussen and S Pedersen-Bjergaard ldquoDevelopmentsin hollow fibre-based liquid-phase microextractionrdquo TrACmdashTrends in Analytical Chemistry vol 23 no 1 pp 1ndash10 2004


[53] D Geng I E Jogsten J Dunstan et al ldquoGas chromatogra-phyatmospheric pressure chemical ionizationmass spectrom-etry for the analysis of organochlorine pesticides and polychlo-rinated biphenyls in human serumrdquo Journal of ChromatographyA vol 1453 pp 88ndash98 2016

[54] G Shen and H K Lee ldquoHollow fiber-protected liquid-phasemicroextraction of triazine herbicidesrdquo Analytical Chemistryvol 74 no 3 pp 648ndash654 2002

[55] D Han and K H Row ldquoTrends in liquid-phase microex-traction and its application to environmental and biologicalsamplesrdquoMicrochimica Acta vol 176 no 1-2 pp 1ndash22 2012

[56] H-J Pan andW-H Ho ldquoDetermination of fungicides in waterusing liquid phase microextraction and gas chromatographywith electron capture detectionrdquo Analytica Chimica Acta vol527 no 1 pp 61ndash67 2004

[57] J Xiong and B Hu ldquoComparison of hollow fiber liquid phasemicroextraction and dispersive liquid-liquid microextractionfor the determination of organosulfur pesticides in environ-mental and beverage samples by gas chromatographywith flamephotometric detectionrdquo Journal of Chromatography A vol 1193no 1-2 pp 7ndash18 2008

[58] A Gure F J Lara N Megersa A M Garcıa-Campana and MDel Olmo-Iruela ldquoHollow-fiber liquid-phase microextractioncombined with capillary HPLC for the selective determinationof six sulfonylurea herbicides in environmental watersrdquo Journalof Separation Science vol 36 no 20 pp 3395ndash3401 2013

[59] A G Frenich R Romero-Gonzalez J LM Vidal RMOcanaand P B Feria ldquoComparison of solid phasemicroextraction andhollow fiber liquid phasemicroextraction for the determinationof pesticides in aqueous samples by gas chromatography triplequadrupole tandem mass spectrometryrdquo Analytical and Bioan-alytical Chemistry vol 399 no 6 pp 2043ndash2059 2011

[60] H L V Capobiango and Z L Cardeal ldquoA solid-phase microex-traction method for the chromatographic determination oforganophosphorus pesticides in fish water potatoes guava andcoffeerdquo Journal of the Brazilian Chemical Society vol 16 no 5pp 907ndash914 2005

[61] M E T Padron C Afonso-Olivares Z Sosa-Ferrera andJ J Santana-Rodrıguez ldquoMicroextraction techniques coupledto liquid chromatography with mass spectrometry for thedetermination of organic micropollutants in environmentalwater samplesrdquoMolecules vol 19 no 7 pp 10320ndash10349 2014

[62] D A Lambropoulou and T A Albanis ldquoLiquid-phase micro-extraction techniques in pesticide residue analysisrdquo Journal ofBiochemical and BiophysicalMethods vol 70 no 2 pp 195ndash2282007

[63] Ministry of Environment pesticide levels in surface water inBrazil CONAMA Resolution No 3582005 httpwwwmmagovbrportconamaresres05res35805pdf

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


(DLLME) [38 39] have been used for the concentration andclean-up step of pesticides analyses in waters HF-LPMEwas developed by Pedersen-Bjergaard and Rasmussen [40]and has been used by many researchers in recent years dueto its low cost which enables the rejection of the materialafter use eliminating problems of cross-contamination orlow reproducibility as well as its decreased consumptionof organic solvents Moreover the process is simple anda clean-up step is not necessary and can be applied to avariety of arrays reaching high enrichment factors [41] Thetechnique consists of a capillary porous hydrophilic fiberimpregnated with organic solvent and its interior filled withan acceptor phase so that it does not come into direct contactwith the matrices allowing for the application of agitationduring extraction [42] HF-LPME can be used in two or threephases With two phases the analyte is extracted from thedonor through an organic solvent immiscible in water thatfills the membrane pores passing to the acceptor stage whichcorresponds to the same solvent [43] With three phasesthe analyte is extracted from a donor phase through anorganic solvent immiscible in water for an aqueous solution(acceptor phase) inside the fiber The organic phase acts asa barrier preventing contact between the phases Despitethe extensive use of HF-LPME for extraction of pesticidesin water [33 44 45] the reported studies using GCMS aregenerally for just one pesticide class Therefore this studypresents the development of a simple and low-cost two-phaseHF-LPME methodology for multiresidue microextractionof organophosphorus phthalimides organochlorines andtriazoles pesticides from environmental water using GCMSThe pesticides selected were parathion-methyl (OO-dimeth-yl-O-p-nitrophenyl phosphorothioate) chlorpyrifos (OO-diethyl O-356-trichloro-2-pyridyl phosphorothioate) cap-tan (N-(trichloromethylthio)cyclohex-4-ene-12-dicarbox-imide) procymidone (N-(35-dichlorophenyl)-12-dimethyl-cyclopropane-12-dicarboximide) 120572-endosulfan (145677-hexachloro-8910-trinorborn-5-en-23-ylenebismethylenesulfite) prothiofos ((RS)-(O-24-dichlorophenyl O-ethylS-propyl phosphorodithioate)) cyproconazole ((2RS3RS2RS3SR)-2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-124-tri-azol-1-yl)butan-2-ol) ethion (OOO1015840O1015840-tetraethyl SS1015840-methylene bis(phosphorodithioate)) triazophos (OO-dieth-yl O-1-phenyl-1H-124-triazol-3-yl phosphorothioate) andphosmet (OO-dimethyl S-phthalimidomethyl phosphorod-ithioate) The main parameters affecting the extractionefficiency were optimized using GCMS determination Theprocedure presented good accuracy and precision and lowlimits of quantification and detection besides good recovery

2 Materials and Methods

21 Chemical andMaterials Parathion-methyl chlorpyrifoscaptan procymidone 120572-endosulfan prothiofos cyprocona-zole ethion triazophos and phosmet of 98ww puritygrade were purchased from Sigma-Aldrich (St Louis MOUSA) The choice of pesticides was based on their useon the region of samples collection A work solution of2000mg Lminus1 was prepared by the appropriate dilution inHPLC-grade methanol Sigma-Aldrich (St Louis Missouri

United States) This work solution was used for the matrixspike in different concentration levels (500 to 16000 120583g Lminus1)to optimize the extraction conditions during the validationstudy Calibration standards were prepared at 500 10002000 4000 8000 and 16000 120583g Lminus1 concentrations usingultrapure water produced in a Purelab UVMK2 purifier fromElga (Marlow Buckinghamshire England) 1-Octanol HPLCgrade was purchased from Sigma-Aldrich (St Louis Mis-souri United States) ethyl decanoate acetonitrile and ethyloctanoate were purchased from J T Baker (Xalostoc EdoMEXMexico) Hollow fiber was purchased fromUnderlyingPerformance Co (Wuppertal Germany)

22 Instrumentation for GCMS The analysis was carriedout with a Shimadzu (Kyoto Japan) GCMS system modelGC-2010QP-2010 high-performance quadrupole The massspectrometer operated within the electron impact mode (EI)at 70 eV A capillary column (30m times 025mm times 025 120583m)containing 5 diphenyl and 95 dimethylpolysiloxane HP-5MS from Agilent Technology Inc (Santa Clara CaliforniaUnited States) was used The oven temperature programbegan at 80∘C and raised to 200∘C at a rate of 8∘Cminminus1up to 300∘C at 30∘Cminminus1 and held there for 3min Helium(99999) was the carrier gas at a flow rate of 10mLminminus1The injector was operated at 280∘C in splitless mode for3min followed by a 1 20 split ratio (RD) The ion sourcetemperature was 200∘C and the GCMS interface tempera-ture was 300∘C The analysis was carried out in the selectedionmonitoring (SIM)modeThe quantification was achievedusing the ion fragments shown in Table 2 The collectionof raw data was carried out using a LabSolution softwareShimadzu (Kyoto Japan)

23 HF-LPME Extraction Procedure Aqueous standards ofpesticides were prepared by spiking an appropriate amountof the working standard The extraction and desorptionconditions were based on Psillakis and Kalogerakisrsquos study[49] LPME sampling was tested in two and three phasesstudy of salt addition stirring speed and extraction timeThe extractions were carried out with propylene hollowfiber of 60 cm length 600 120583m of internal diameter andwall thickness of 200120583m Before the extraction the hollowfiber was filled with 300 120583L of solvent using a microsyringeThen the U-shaped solvent-filled fiber was connected totwo syringe needles and immersed into the vial containing1500mL of aqueous donor solutions spiked with 1000 120583g Lminus1of standard pesticides solutions for the extraction undermagnetic stirring After the extraction the acceptor phasewas removed with a microsyringe and transferred to a 20mLvial to the injection of 10 120583L in GCMS All experiments wereperformed in replicates (119899 = 3)

24 Samples Collection Real samples of surface water werecollected in a rural area of the state of Minas Gerais BrazilIn this region the main crops are coffee eucalyptus andtomatoes Samples of surface water were sampled 2 kmdown-stream of these crops The collected samples showed clearappearance and no suspended particles The amber-glass









Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

Pesticides


times107

00

02

04

06

08

10

12

Peak

area

1-Octanol





Table1Ph

ysicochemicalprop

ertie

softhe

selected

pesticides

Pesticide

CASnu

mber

Chem

icalcla

ssMolecular

form

ula

Structuralform

ula

log119870

owWater

solubility(m

gLminus1

)

Triazoph

os24017-47-8

Organop

hospho

rus

C 12

H16

N3

O3

PSN

NN

OOO P

S

CH

3

CH

3

334

3500

Prothiofos

34643-46

-4Organop

hospho

rus

C 11

H15

Cl2

O2

PS2

Cl

ClSS P

O

O567

007

Chlorpyrifo

s2921-88-2

Organop

hospho

rus

C 9H11

Cl3

NO3

PSN

OO

OPS

ClCl

Cl470

105

Parathion-methyl

298-00-0

Organop

hospho

rus

C 8H10

NO5

PSO

OO O

PS

N+ O

minus

286

377

Captan

133-06-2

Dicarbo

ximide

C 9H8

Cl3

NO2

S

ClCl Cl

SNO O

250

520

Cyprocon

azole

94361-0

6-5

Triazole

C 15

H18

ClN3

O

Cl

HO

NN

N

309

9300


Table1Con

tinued

Pesticide

CASnu

mber

Chem

icalcla

ssMolecular

form

ula

Structuralform

ula

log119870

owWater

solubility(m

gLminus1

)

Ethion

563-12-2

Organop

hospho

rus

C 9H22

O4

P 2S 4

OO

OO

PP

SS

SS

507

200

Procym

idon

e32809-16-8

Dicarbo

ximide

C 13

H11

Cl2

NO2

Cl

Cl

O

ON

330

246

120572-End

osulfan

115-29-7

Organochloride

C 9H6

Cl6

O3

SOO

O

Cl

ClCl

Cl

Cl

Cl

H H

S475

032

Phosmet

732-11-6

Organop

hospho

rus

C 11

H12

NO4

PS2

NO

OOO

PS

S296

1520



Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

0 rpm200 rpm400 rpm

800 rpm1600 rpm

times106

0

1

2

3

4

5

6

7

Peak

area







Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met



times106

0

1

2

3

Peak

area


Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

times106

00

05

10

15

20

25

30

35

Peak

area

10 min20 min30 min

40 min60 min


1

0

25

50

75

100

Inte

nsity

10

987

654

3

2

150125 175 200 225 250100

Time (min)

(a)

0

25

50

75

100

Inte

nsity

95

1

125 150 175 200 225 250100

Time (min)

(b)







Extractionmethod










4 Conclusions


Competing Interests



Acknowledgments


References













































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of









Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

Pesticides


times107

00

02

04

06

08

10

12

Peak

area

1-Octanol





Table1Ph

ysicochemicalprop

ertie

softhe

selected

pesticides

Pesticide

CASnu

mber

Chem

icalcla

ssMolecular

form

ula

Structuralform

ula

log119870

owWater

solubility(m

gLminus1

)

Triazoph

os24017-47-8

Organop

hospho

rus

C 12

H16

N3

O3

PSN

NN

OOO P

S

CH

3

CH

3

334

3500

Prothiofos

34643-46

-4Organop

hospho

rus

C 11

H15

Cl2

O2

PS2

Cl

ClSS P

O

O567

007

Chlorpyrifo

s2921-88-2

Organop

hospho

rus

C 9H11

Cl3

NO3

PSN

OO

OPS

ClCl

Cl470

105

Parathion-methyl

298-00-0

Organop

hospho

rus

C 8H10

NO5

PSO

OO O

PS

N+ O

minus

286

377

Captan

133-06-2

Dicarbo

ximide

C 9H8

Cl3

NO2

S

ClCl Cl

SNO O

250

520

Cyprocon

azole

94361-0

6-5

Triazole

C 15

H18

ClN3

O

Cl

HO

NN

N

309

9300


Table1Con

tinued

Pesticide

CASnu

mber

Chem

icalcla

ssMolecular

form

ula

Structuralform

ula

log119870

owWater

solubility(m

gLminus1

)

Ethion

563-12-2

Organop

hospho

rus

C 9H22

O4

P 2S 4

OO

OO

PP

SS

SS

507

200

Procym

idon

e32809-16-8

Dicarbo

ximide

C 13

H11

Cl2

NO2

Cl

Cl

O

ON

330

246

120572-End

osulfan

115-29-7

Organochloride

C 9H6

Cl6

O3

SOO

O

Cl

ClCl

Cl

Cl

Cl

H H

S475

032

Phosmet

732-11-6

Organop

hospho

rus

C 11

H12

NO4

PS2

NO

OOO

PS

S296

1520



Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

0 rpm200 rpm400 rpm

800 rpm1600 rpm

times106

0

1

2

3

4

5

6

7

Peak

area







Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met



times106

0

1

2

3

Peak

area


Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

times106

00

05

10

15

20

25

30

35

Peak

area

10 min20 min30 min

40 min60 min


1

0

25

50

75

100

Inte

nsity

10

987

654

3

2

150125 175 200 225 250100

Time (min)

(a)

0

25

50

75

100

Inte

nsity

95

1

125 150 175 200 225 250100

Time (min)

(b)







Extractionmethod










4 Conclusions


Competing Interests



Acknowledgments


References













































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Table1Ph

ysicochemicalprop

ertie

softhe

selected

pesticides

Pesticide

CASnu

mber

Chem

icalcla

ssMolecular

form

ula

Structuralform

ula

log119870

owWater

solubility(m

gLminus1

)

Triazoph

os24017-47-8

Organop

hospho

rus

C 12

H16

N3

O3

PSN

NN

OOO P

S

CH

3

CH

3

334

3500

Prothiofos

34643-46

-4Organop

hospho

rus

C 11

H15

Cl2

O2

PS2

Cl

ClSS P

O

O567

007

Chlorpyrifo

s2921-88-2

Organop

hospho

rus

C 9H11

Cl3

NO3

PSN

OO

OPS

ClCl

Cl470

105

Parathion-methyl

298-00-0

Organop

hospho

rus

C 8H10

NO5

PSO

OO O

PS

N+ O

minus

286

377

Captan

133-06-2

Dicarbo

ximide

C 9H8

Cl3

NO2

S

ClCl Cl

SNO O

250

520

Cyprocon

azole

94361-0

6-5

Triazole

C 15

H18

ClN3

O

Cl

HO

NN

N

309

9300


Table1Con

tinued

Pesticide

CASnu

mber

Chem

icalcla

ssMolecular

form

ula

Structuralform

ula

log119870

owWater

solubility(m

gLminus1

)

Ethion

563-12-2

Organop

hospho

rus

C 9H22

O4

P 2S 4

OO

OO

PP

SS

SS

507

200

Procym

idon

e32809-16-8

Dicarbo

ximide

C 13

H11

Cl2

NO2

Cl

Cl

O

ON

330

246

120572-End

osulfan

115-29-7

Organochloride

C 9H6

Cl6

O3

SOO

O

Cl

ClCl

Cl

Cl

Cl

H H

S475

032

Phosmet

732-11-6

Organop

hospho

rus

C 11

H12

NO4

PS2

NO

OOO

PS

S296

1520



Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

0 rpm200 rpm400 rpm

800 rpm1600 rpm

times106

0

1

2

3

4

5

6

7

Peak

area







Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met



times106

0

1

2

3

Peak

area


Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

times106

00

05

10

15

20

25

30

35

Peak

area

10 min20 min30 min

40 min60 min


1

0

25

50

75

100

Inte

nsity

10

987

654

3

2

150125 175 200 225 250100

Time (min)

(a)

0

25

50

75

100

Inte

nsity

95

1

125 150 175 200 225 250100

Time (min)

(b)







Extractionmethod










4 Conclusions


Competing Interests



Acknowledgments


References













































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Table1Con

tinued

Pesticide

CASnu

mber

Chem

icalcla

ssMolecular

form

ula

Structuralform

ula

log119870

owWater

solubility(m

gLminus1

)

Ethion

563-12-2

Organop

hospho

rus

C 9H22

O4

P 2S 4

OO

OO

PP

SS

SS

507

200

Procym

idon

e32809-16-8

Dicarbo

ximide

C 13

H11

Cl2

NO2

Cl

Cl

O

ON

330

246

120572-End

osulfan

115-29-7

Organochloride

C 9H6

Cl6

O3

SOO

O

Cl

ClCl

Cl

Cl

Cl

H H

S475

032

Phosmet

732-11-6

Organop

hospho

rus

C 11

H12

NO4

PS2

NO

OOO

PS

S296

1520



Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

0 rpm200 rpm400 rpm

800 rpm1600 rpm

times106

0

1

2

3

4

5

6

7

Peak

area







Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met



times106

0

1

2

3

Peak

area


Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

times106

00

05

10

15

20

25

30

35

Peak

area

10 min20 min30 min

40 min60 min


1

0

25

50

75

100

Inte

nsity

10

987

654

3

2

150125 175 200 225 250100

Time (min)

(a)

0

25

50

75

100

Inte

nsity

95

1

125 150 175 200 225 250100

Time (min)

(b)







Extractionmethod










4 Conclusions


Competing Interests



Acknowledgments


References













































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

0 rpm200 rpm400 rpm

800 rpm1600 rpm

times106

0

1

2

3

4

5

6

7

Peak

area







Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met



times106

0

1

2

3

Peak

area


Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

times106

00

05

10

15

20

25

30

35

Peak

area

10 min20 min30 min

40 min60 min


1

0

25

50

75

100

Inte

nsity

10

987

654

3

2

150125 175 200 225 250100

Time (min)

(a)

0

25

50

75

100

Inte

nsity

95

1

125 150 175 200 225 250100

Time (min)

(b)







Extractionmethod










4 Conclusions


Competing Interests



Acknowledgments


References













































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met



times106

0

1

2

3

Peak

area


Para

thio

n-m

ethy

l

Chlo

rpyr

ifos

Capt

an

Proc

ymid

one

120572-E

ndos

ulfa

n

Prot

hiof

os

Cypr

ocon

azol

e

Ethi

on

Tria

zoph

os

Phos

met

times106

00

05

10

15

20

25

30

35

Peak

area

10 min20 min30 min

40 min60 min


1

0

25

50

75

100

Inte

nsity

10

987

654

3

2

150125 175 200 225 250100

Time (min)

(a)

0

25

50

75

100

Inte

nsity

95

1

125 150 175 200 225 250100

Time (min)

(b)







Extractionmethod










4 Conclusions


Competing Interests



Acknowledgments


References













































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



Extractionmethod










4 Conclusions


Competing Interests



Acknowledgments


References













































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Acknowledgments


References













































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

Research Article A Simple and Quick Method for the...

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