Food Chemistry 160 (2014) 379–392

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Food Chemistry

journal homepage: www.elsevier .com/locate / foodchem

Pesticide residues in fruits and vegetables from the Aegean region,Turkey

http://dx.doi.org/10.1016/j.foodchem.2014.02.0510308-8146/� 2014 Elsevier Ltd. All rights reserved.

⇑ Corresponding author. Tel.: +90 2324610900.E-mail addresses: gozde.turkoz@naturalab.com.tr (G.T. Bakırcı), bengu.yaman@

naturalab.com.tr (D.B. Yaman Acay), fatih.bakirci@naturalab.com.tr (F. Bakırcı),semih.otles@ege.edu.tr (S. Ötles�).

Gözde Türköz Bakırcı a,⇑, Dilek Bengü Yaman Acay a, Fatih Bakırcı a, Semih Ötles� b

a Food Control and Research Laboratory, Aybak Natura, Izmir, Turkeyb Department of Food Engineering, Ege University, 35100 Izmir, Bornova, Turkey

a r t i c l e i n f o a b s t r a c t

Article history:Received 30 September 2013Received in revised form 9 February 2014Accepted 12 February 2014Available online 22 February 2014

Keywords:Pesticides residuesUPLC–MS/MSGC–ECD/GC–MSFruits and vegetables

The purpose of this study was to investigate pesticide residues in fruits and vegetables from the Aegeanregion of Turkey. A total of 1423 samples of fresh fruit and vegetables were collected from 2010 to 2012.The samples were analysed to determine the concentrations of 186 pesticide residues. The analyses uti-lized ultrahigh performance liquid chromatography coupled with tandem mass spectrometry (UPLC/MS/MS) and gas chromatography with an electron capture detector (GC–ECD) confirmed by gas chromatog-raphy with mass spectrometry (GC–MS) after a multi-residue extraction procedure (the QuEChERSmethod). The results were evaluated according to maximum residue limits (MRLs) for each commodityand pesticide by Turkish Regulation. All pomegranate, cauliflower and cabbage samples were pesti-cides-free. A total of 754 samples contained detectable residues at or below MRLs, and 48 (8.4%) of thefruit samples and 83 (9.8%) of the vegetable samples contained pesticide residues above MRLs. MRL val-ues were most often exceeded in arugula, cucumber, lemon, and grape commodities. All detected pesti-cides in apricot, carrot, kiwifruit and leek were below the MRLs. Acetamiprid, chlorpyriphos andcarbendazim were the most detected pesticide residues.

� 2014 Elsevier Ltd. All rights reserved.

1. Introduction

Pesticides are chemical substances applied to crops at variousstages of cultivation and during the post-harvest storage of crops.The use of pesticides is intended to prevent the destruction of foodcrops by controlling agricultural pests or unwanted plants and toimprove plant quality (Bakirci & Hisil, 2011). Pesticide use in com-mercial agriculture has led to an increase in farm productivity.Despite the wide ranging benefits of using pesticides in agriculture,several incorrect applications can result in high and undesirablelevels of the compounds in the produce that reaches consumers.These include inappropriate selection of pesticides used on food-stuffs, over use of pesticides and harvesting the crops before theresidues have washed off after application (Chen et al., 2011;Cserháti, Forgács, Deyl, Miksik, & Eckhardt, 2004). Exposure to pes-ticides can occur via a number of pathways such as indirect (e.g.,through food, drinking water, residential and occupational expo-sure) and direct routes (oral, inhalation and dermal). However,the major concerns are from consumption of pesticide laden food

crops (Boobis et al., 2008). Pesticides have been linked to a widespectrum of human health hazards, ranging from acute impacts,such as headaches and nausea, to chronic impacts, such as cancer,reproductive harm and endocrine system disruption (Blasco, Font,& Picó, 2006). In addition, incorrect applications of pesticides maycause harm to the environment, increased resistance in the targetpest organisms and deleterious effects on non-target organisms. Toensure the safety of food for consumers and to protect consumerhealth, the monitoring of pesticide residues in food products mustbe pursued. Therefore, the levels of pesticide residues allowed infoodstuffs are legislatively controlled through setting maximumresidue levels (MRLs). These MRLs limit the types and amount ofpesticides that can be legally present on foods, as determined byvarious regulatory bodies which minimize consumer exposure toharmful or unnecessary intake of pesticides worldwide. In addi-tion, MRLs help ensure the proper use of pesticides through autho-rization and registration (application rates and pre-harvest timeintervals) and permit the free circulation of pesticide-treatedproducts (Kmellára, Abrankóa, Fodora, & Lehotay, 2010; Knezevic& Serdar, 2009).

Many studies have investigated and identified pesticide resi-dues in animals or crop plant products, such as fruit and vegeta-bles, wheat, milk, cheese, butter, eggs, honey, meat and meatproducts from various countries (Ahmad, Salem, & Estaitieh,

380 G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392

2010; Bai, Zhou, & Wang, 2006; Blasco et al., 2004; Chen et al.,2011; Darko & Acquaah, 2008; Hjorth et al., 2011; Knezevic &Serdar, 2009; Mallatou, Pappas, Kondyli, & Albanisb, 1997; Osman,Al-Humaid, Al-Rehiayani, & Al-Redha, 2010; Picó, la Farré, Soler, &Barceló, 2007). However, limited information is available regardingpesticide residue contamination in Turkey (Bulut, Akkaya, Gok, &Konuk, 2010; Erdogrul, Covaci, & Schepens, 2005; Guler, Cakmak,Dagli, Aktumsek, & Ozparlak, 2010; Yentur, Kalay, & Oktem,2001). In particular, there is no published literature regarding pes-ticide residues on fruits and vegetables in Turkey. Fruit and vege-tables often contain higher pesticide residue levels compared toother food groups (Chen et al., 2011).

The aim of this study was to investigate the presence of pesti-cide residues on fruit and vegetables. A totally of 1423 sampleswere collected from the market from 2010–2012. A total of 186commonly used pesticide active substances were selected. Thenames of the pesticides and crop samples are listed in Tables 1and 2. These samples were analysed by UPLC/MS–MS and GC–ECD/GC–MS to determine if they were in compliance with existingregulations limiting the total amount of pesticide residues legallyallowed on food crops used for human consumption.

2. Materials and methods

2.1. Chemicals and reagents

All solvents and reagents were of pesticide grade and were dis-solved as required for the sample extraction protocol and prepara-tion of mobile phases. Anhydrous magnesium sulphate (MgSO4),acetonitrile (MeCN), glacial acetic acid (HOAc), anhydrous sodiumacetate (NaAc) and a graphitised carbon black (GCB) sorbent wereobtained from Merck (Darmstadt, Germany). Methanol and deion-ised water was purchased from JT Baker (Deventer, Netherlands)and primary secondary amine (PSA) sorbent was from Oxoid(London, England). Pesticide standards were purchased fromDr. Ehrenstorfer (Augsburg, Germany). The purities of all pesticidestandards were greater than 98%.

2.2. Preparation of standard solutions

Stock standard solutions were prepared at 1000 mg kg�1 by dis-solving 10 mg of each compound into 10 ml of solvent. From theindividual stock standard solutions, a multi-compound standardsolution was prepared with a concentration of 5 mg L�1. The work-ing standard solutions that were used for preparation of the matrixmatched standards within a range between 2.5 to 200 lg L�1.

2.3. Fruit and vegetable samples

A total of 1423 samples of different fresh fruits and vegetableswere randomly collected from a market in the Aegean region ofTurkey from 2010–2012. All samples were taken in accordancewith the Turkish regulation (Ministry Of Agriculture & Rural AffairsGeneral Directorate Of Protection & Control, 2006/51). These sam-ples were transported to the test laboratory under cold conditionsand kept at 4 �C. They were analysed within 24 h from their arrivalfor the presence of pesticide residues following the procedure de-scribed below.

2.4. Instruments and apparatus

2.4.1. General instrumentsA Heidolph Reax 2000 vortex mixer (Schwabach, Germany),

Sartorius CP225D and ED323S-CW analytical balances, and anEppendorf 5702 centrifuge (Hamburg, Germany) were used.

Additionally, a freezer, pipettes, spatulas, funnels, polypropylenecentrifuge tubes, gloves, beakers, filters and vials were neededfor the extraction protocol. LC–MS/MS, GC–ECD, and GC–MS wereused for the chromatographic analyses.

2.4.2. LC–MS/MS instruments and apparatusFor LC–MS/MS, an ACQUITY TQD tandem quadrupole mass

spectrometer (Waters, Manchester, UK) was used. The systemwas equipped with a quaternary pump, a vacuum degasser and athermostated autosampler. For the chromatographic separation, aWaters Acquity UPLC BEH C18 column (100 mm � 2.1 mm, 1.7lm particle size) was employed. The instrument was operatedusing an electrospray ionisation source (ESI) in the positive andnegative mode. The ESI parameters were: capillary voltage3.5 kV, extractor voltage 3 V, source temperature 140 �C, desolva-tion temperature 450 �C, cone gas flow 200 L h�1 and desolvationgas flow 1050 L h�1 (both gases were nitrogen). Collision-induceddissociation was performed using argon as the collision gas at apressure of 4 � 10�3 mbar in the collision cell.

Chromatographic analyses were conducted using gradient elu-tion with eluent A composed of methanol (5%) and water with 2mm ammonium acetate (95%), and eluent B was composed ofmethanol (95%) and water with 2 mm ammonium acetate (5%).The gradient elution programme started with 100% of eluent Aand 100% of eluent B in 10.0 min. This composition was held foran additional 2.5 min before being returned to 100% of eluent A,for a total run time of 15 min. The flow rate of 0.45 ml min�1

was used for the separation of analytes. The column temperaturewas maintained at 50 �C. A 20-ll volume of the extracted samplewas injected.

2.4.3. Gas chromatography instruments and apparatusThe GC analysis was conducted using a GC–electron capture

detector (ECD), and the detected pesticides were confirmed byGC–MS. The GC–ECD analyses were performed on a Agilent6890 N equipped with a split/splitless injector and a 7683B autoin-jector (Agilent, Santa Clara, USA). The GC–MS analysis was per-formed on an Agilent 7890A Turbo MSD 5975C equipped with aPTV Inlet and a 7683B autoinjector (Agilent, Santa Clara, USA). He-lium was used as the carrier gas at a flow rate of 1.0 ml/min. Argonwas used as the collision gas. Separations were conducted using aHP 5-MS 30 m � 0.25 mm � 0.25 ll column for GC–ECD and HP5-MS Ultra Inert 30 m � 0.25 mm � 0.25 ll column (Agilent, SantaClara, USA) for the GC–MS. The injection volume was 25 ll, and theinjector temperature was held at 280 �C. Samples were analysed asfollows: the temperature programme was set for an initial temper-ature of 70 �C (held for 2 min), increased to 150 �C at 25 �C/min(held for 1 min), raised to 200 �C at 3 �C/min (held for 1 min) and,finally, increased to 280 �C at 8 �C/min (held for 15 min) for theGC–ECD and GC–MS analyses.

2.5. Extraction procedure

All samples that was unwashed and with the peel intact, basedon the definition of Turkish regulation (Ministry Of Agriculture &Rural Affairs General Directorate Of Protection & Control, 2009/62), were homogenised using a blender (Waring, DCA, CT, USA)for more than 1 min to obtain thoroughly mixed homogenates.Homogenised samples were analysed according to the QuEChERSprocedure (Lehotay, 2007). Briefly, fifteen grammes of homoge-nised sample was weighed in a 50 ml polypropylene centrifugetubes. Next, 15 ml of 1% HOAc (10 ml glacial HOAc in a 1 L MeCNsolution) were added with 6 g anh. MgSO4 + 1.5 g anh. NaAc andthe tube was closed. The samples were shaken in a vortex for1 min and centrifuged for 1 min at 1.6 rcf. A 2 ml volume ofsupernatant was removed to the polypropylene centrifuge tubes

Table 1Selected pesticides, analysis instrument, their properties, solvent and use.

Analytes Analysed by Solvent Pesticide class Usea LOD rangeb LOQ rangeb

2,40-DDT GC–ECD Methanol Organochlorine I 0.31–0.72 1.04–2.404,40-DDD GC–ECD Methanol Organochlorine I 0.83–1.61 2.75–5.374,40-DDE GC–ECD Methanol Organochlorine I 1.17–1.35 3.91–4.494,40-DDT GC–ECD Methanol Organochlorine I 0.15–0.58 0.50–1.92Alpha cypermethrin GC–ECD Acetonitril Pyrethroid I 0.64–1.39 2.14–4.62Bromopropylate GC–ECD Acetonitril Benzilate A 0.59–0.98 1.95–3.26Captan GC–ECD Acetonitril Phthalimide F 0.30–0.91 0.99–3.05Chlorothalonil GC–ECD Acetonitril Chloronitrile F 0.50–1.83 1.68–6.09Chlorpropham GC–ECD Methanol Carbamate H, PR 0.37–0.84 1.22–2.81Chlorpyriphos GC–ECD Methanol Organophosphorous I 0.42–1.40 1.41–4.66Chlorpyriphos methyl GC–ECD Methanol Organophosphorous I 0.17–0.87 0.55–0.88Cyfluthrin GC–ECD Acetonitril Pyrethroid I 0.70–1.72 2.32–5.72Cypermethrin GC–ECD Acetonitril Pyrethroid I 0.62–1.43 2.07–4.75Deltamethrin GC–ECD Acetonitril Pyrethroid I 1.16–2.31 3.86–7.70Diazinon GC–ECD Acetonitril Organophosphorous A, I, N 0.94–2.08 3.12–6.94Dicloran GC–ECD Acetonitril Chlorophenyl F 0.66–1.18 2.19–3.93Dicofol GC–ECD Acetonitril Organochlorine A 0.77–0.93 2.56–3.10Dinobuton GC–ECD Acetonitril Dinitrophenol A, F 0.85–1.52 2.83–5.06Endosulfan sulfate GC–ECD Acetonitril Cyclodiene, organochlorine I 0.50–1.88 1.68–6.28Endosulfan alpha GC–ECD Acetonitril Organochlorine A, I 0.65–1.79 2.17–5.98Endosulfan beta GC–ECD Acetonitril Organochlorine A, I 0.66–1.43 2.20–4.78Esfenvalerate GC–ECD Methanol Pyrethroid A, I 0.37–1.03 1.22–3.44Ethion GC–ECD Acetonitril Organophosphorous A, I 0.59–1.36 1.98–4.53Fenarimol GC–ECD Acetonitril Pyrimidine F 1.06–1.58 3.54–5.27Fenitrothion GC–ECD Acetonitril Organophosphorous I 0.91–2.15 3.02–7.15Fenpropathrin GC–ECD Acetonitril Pyrethroid A, I 0.97–1.58 3.22–5.26Fenvalerate GC–ECD Acetonitril Pyrethroid A, I 0.83–1.56 2.76–5.21Folpet GC–ECD Acetonitril Phthalimide F 0.73–1.42 2.44–4.74Formothion GC–ECD Acetonitril Organophosphorous A, I 0.35–0.81 1.15–2.69Gamma HCH GC–ECD Acetonitril Organochlorine I 0.63–1.16 2.10–3.86Iprodione GC–ECD Acetonitril Dicarboximide F 0.44–1.36 1.45–4.53Lambda cyhalothrin GC–ECD Acetonitril Pyrethroid I 0.83–0.98 2.78–3.26Malathion GC–ECD Acetonitril Organophosphorous A, I 0.22–1.14 0.72–3.79Parathion ethyl GC–ECD Acetonitril Organophosphorous A, I 0.82–1.48 2.72–4.92Parathion methyl GC–ECD Acetonitril Organophosphorous I 0.72–1.70 2.38–5.67Permethrin GC–ECD Acetonitril Pyrethroid I 0.76–1.42 2.54–4.72Procymidone GC–ECD Acetonitril Dicarboximide F 0.43–1.03 1.44–3.42Prothiophos GC–ECD Acetonitril Organophosphorous I 0.74–1.66 2.47–5.53Quinomethionate GC–ECD Acetonitril Quinoline A, F 0.71–0.97 2.36–3.25Taufluvalinate GC–ECD Acetonitril Pyrethroid A, I 0.39–1.94 1.31–6.45Tetradifon GC–ECD Acetonitril Unclassified A 0.46–1.29 1.53–4.29Trifluralin GC–ECD Acetonitril Dinitroaniline H 0.60–1.16 2.02–3.87Vinclozolin GC–ECD Acetonitril Dicarboximide F 0.59–1.07 1.95–3.562,4-Acid UPLC–MS/MS Acetonitril Aryloxyalkanoic acid/ester H, PR 0.67–0.93 2.23–3.10Acetamiprid UPLC–MS/MS Methanol Neonicotinoid I 0.70–1.49 2.34–4.98Alachlor UPLC–MS/MS Methanol Chloroacetamide H 0.74–1.02 2.47–3.41Aldicarb UPLC–MS/MS Methanol Oxime carbamate A, I, N 0.80–0.87 2.66–2.89Allethrin UPLC–MS/MS Methanol Pyrethroid I 0.45–1.56 1.49–5.19Amitraz UPLC–MS/MS Methanol Amidine A, I 0.36–0.96 1.20–3.19Atrazine UPLC–MS/MS Methanol Triazine H 0.83–1.26 2.75–4.19Azoxystrobin UPLC–MS/MS Methanol Strobilurin F 0.68–1.54 2.25–5.15Bensulfuron-methyl UPLC–MS/MS Methanol Sulfonylurea H 0.70–1.62 2.34–5.41Bifenthrin UPLC–MS/MS Methanol Pyrethroid A, I 0.37–0.60 1.22–2.00Boscalid UPLC–MS/MS Methanol/Acetonitrile Pyridinecarboxamide F 0.75–1.39 2.50–4.63Bupirimate UPLC–MS/MS Methanol Pyrimidinol F 0.41–0.65 1.36–2.17Buprofezine UPLC–MS/MS Methanol Thiadiazin A, I 0.76–1.01 2.53–3.36Butralin UPLC–MS/MS Acetonitril Dinitroaniline H, PR 0.70–1.47 2.33–4.90Cadusafos UPLC–MS/MS Methanol Organophosphorous I, N 0.46–1.04 1.52–3.45Carbaryl UPLC–MS/MS Methanol Carbamate A, PR, I 0.85–1.00 2.85–3.35Carbendazim/Benomyl UPLC–MS/MS Methanol Benzimidazole F 0.58–1.74 1.93–5.79Carbofuran UPLC–MS/MS Methanol Carbamate, N-methyl A, I, N 1.02–1.26 3.41–4.18Carbosulfan UPLC–MS/MS Methanol Carbamate I 0.87–1.74 2.91–5.80Carfentrazone-ethyl UPLC–MS/MS Methanol/Acetonitrile Triazolinone H 0.63–1.73 2.11–5.78Chlofentezine UPLC–MS/MS Methanol Tetrazine A 0.66–1.38 2.19–4.59Chlorbromuron UPLC–MS/MS Acetonitril Urea H 0.45–1.42 1.50–4.73Chlorfluazuron UPLC–MS/MS Methanol Benzoylurea I 0.54–0.71 1.79–2.37Chloroxuron UPLC–MS/MS Methanol Urea H 0.54–0.86 1.80–2.88Chlorsulfuron UPLC–MS/MS Acetonitril Sulfonylurea H 0.73–0.78 2.44–2.59Cinidon-ethyl UPLC–MS/MS Acetonitril Phthalimide H 0.93–1.26 3.11–4.20Clefoxydim UPLC–MS/MS Acetonitril Cyclohexanedione oxime H 0.69–1.67 2.28–5.58Clodinafop-propargyl UPLC–MS/MS Methanol Aryloxyphenoxypropionic acid/ester H 1.00–1.08 3.34–3.61Clofentezine UPLC–MS/MS Methanol Tetrazine A 0.92–1.58 3.06–5.26Clomazone UPLC–MS/MS Methanol Isoxazolidinone H 0.65–1.34 2.18–4.46Cycloate UPLC–MS/MS Methanol Thiocarbamate H 0.62–1.57 2.07–5.22

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Cycloxydim UPLC–MS/MS Acetonitril Cyclohexanedione oxime H 0.78–1.09 2.61–3.64Cymoxanil UPLC–MS/MS Methanol Unclassified F 1.44–1.65 4.81–5.51Cyproconazole UPLC–MS/MS Methanol Triazole F 0.57–1.02 1.90–3.41Cyprodinil UPLC–MS/MS Methanol Anilinopyrimidine F 0.83–2.24 2.77–7.48Demeton-S-methyl UPLC–MS/MS Methanol Organophosphorous A, I 0.46–2.56 1.54–8.55Desmedipham UPLC–MS/MS Methanol Bis-carbamate H 0.89–1.06 2.97–3.54Diazinon UPLC–MS/MS Acetonitril Organophosphorous A, I,N 1.56–2.28 5.21–7.62Dichlofluanid UPLC–MS/MS Acetonitril Sulphamide F 0.67–1.35 2.24–4.51Dichlorvos(DDVP) UPLC–MS/MS Acetonitril Organophosphorous A, I 0.58–0.94 1.94–3.14Difenaconazole UPLC–MS/MS Methanol Triazole F 0.56–0.84 7.65–11.92Dimethoate UPLC–MS/MS Acetonitril Organophosphorous A, I 0.67–0.96 2.24–3.21Dimethomorph UPLC–MS/MS Methanol Cinnamic acid F 0.71–1.25 2.37–4.18Diniconazole UPLC–MS/MS Methanol Triazole F 2.14–2.67 7.15–8.92Dinocap UPLC–MS/MS Methanol Dinitrophenol A, F 2.29–3.57 7.65–11.92Diphenamid UPLC–MS/MS Methanol Alkanimide H 0.31–1.05 1.04–3.51Diphenylamine UPLC–MS/MS Acetonitril Amine F 0.51–0.64 1.70–2.14Dithianon UPLC–MS/MS Acetonitril Quinone F 0.22–0.56 0.74–1.87Diuron UPLC–MS/MS Acetonitril Urea H 0.37–0.82 1.24–2.74Epoxiconazole UPLC–MS/MS Methanol Triazole F 2.54–2.93 8.48–9.79EPTC UPLC–MS/MS Acetonitril Thiocarbamate H 1.09–1.64 3.64–5.48Ethiofencarb UPLC–MS/MS Methanol Carbamate, N-methyl I 2.01–2.85 6.71–9.52Ethofumesate UPLC–MS/MS Methanol Benzofuran H 0.64–0.78 2.14–2.61Famoxadone UPLC–MS/MS Methanol Strobilurin F 0.37–0.95 1.4–3.17Fenarimol UPLC–MS/MS Acetonitril Pyrimidine F 0.84–0.93 2.81–3.11Fenazaquin UPLC–MS/MS Methanol Quinazoline A 0.45–0.67 1.50–2.24Fenbuconazole UPLC–MS/MS Methanol Triazole F 1.08–1.59 3.61–5.31Fenchlorazole UPLC–MS/MS Methanol/Acetonitrile Unclassified H 0.57–0.91 1.90–3.04Fenoxaprop-P-ethyl UPLC–MS/MS Acetonitril Aryloxyphenoxypropionic acid/ester H 0.41–1.43 1.37–4.78Fenoxycarb UPLC–MS/MS Methanol Carbamate I 0.32–0.66 1.07–2.20Fenthion UPLC–MS/MS Methanol Organophosphorous I 1.09–2.14 3.65–7.15Fluazifop-P-butyl UPLC–MS/MS Acetonitril Aryloxyphenoxypropionic acid/ester H 0.59–0.78 1.97–2.61Fluazinam UPLC–MS/MS Methanol/Acetonitrile Phenylpyridinamine F 0.27–0.68 0.90–2.27Fludioxonyl UPLC–MS/MS Methanol Phenylpyrrole F 1.09–1.65 3.64–5.51Flufenoxuron UPLC–MS/MS Acetonitril Benzoylurea A, I 0.87–2.12 2.91–7.08Fluometuron UPLC–MS/MS Methanol Phenylurea H 0.39–0.64 1.30–2.14Flurochloridone UPLC–MS/MS Acetonitril Unclassified H 0.94–2.35 3.14–7.85Flusilazole UPLC–MS/MS Acetonitril Triazole F 0.65–0.98 2.17–3.27Flutriafol UPLC–MS/MS Acetonitril Triazole F 0.34–0.85 1.14–2.84Furathiocarb UPLC–MS/MS Methanol Carbamate I 0.39–0.49 1.30–1.64Haloxyfop-R-methyl UPLC–MS/MS Acetonitril Aryloxyphenoxypropionic acid/ester H 1.06–2.17 3.54–7.25Hexythiazox UPLC–MS/MS Methanol Unclassified A 1.29–1.67 4.31–5.58Imazalil UPLC–MS/MS Methanol/Acetonitrile Imidazole F 0.65–0.94 2.17–3.14Imazethapyr UPLC–MS/MS Acetonitril Imidazolinone H 1.64–1.98 5.48–6.61Imidacloprid UPLC–MS/MS Methanol Neonicotinoid I 1.35–1.82 4.51–6.08Iodosulfuron-methyl UPLC–MS/MS Acetonitril Sulfonylurea H 0.65–0.98 2.17–3.27Ioxynil UPLC–MS/MS Acetonitril Hydroxybenzonitrile H 0.51–0.85 1.70–2.84Isoxaflutole UPLC–MS/MS Acetonitril Isoxazole H 0.78–0.96 2.61–3.21Indoxacarb UPLC–MS/MS Methanol Oxadiazine I 1.25–1.55 4.18–5.18Kresoxim-methyl UPLC–MS/MS Methanol/Acetonitrile Strobilurin F 0.29–0.64 0.97–2.14Lenacil UPLC–MS/MS Acetonitril Uracil H 0.35–0.98 1.17–3.27Lufenuron UPLC–MS/MS Methanol Benzoylurea A, I 1.34–1.55 4.48–5.18MCPA UPLC–MS/MS Acetonitril Aryloxyalkanoic acid/ester H 1.97–2.29 6.58–7.65Mefenpyr-diethyl UPLC–MS/MS Methanol/Acetonitrile Herbicide safener H 0.69–2.65 2.31–8.85Metalaxyl UPLC–MS/MS Methanol/Acetonitrile Acylalanine F 0.58–0.67 1.94–2.24Metalaxyl-M UPLC–MS/MS Methanol/Acetonitrile Acylalanine F 0.94–2.25 3.14–7.52Methiocarb UPLC–MS/MS Acetonitril Carbamate, N-methyl A, I, M 0.37–1.58 1.24–5.28Methomyl UPLC–MS/MS Methanol/Acetonitrile Oxime carbamate A, I 0.45–1.05 1.50–3.51Metolachlor UPLC–MS/MS Methanol/Acetonitrile Chloroacetamide H 0.74–1.26 2.47–4.21Metribuzin UPLC–MS/MS Methanol Triazinone H 0.29–0.84 0.97–2.81Metsulfuron-methyl UPLC–MS/MS Acetonitril Triazinylsulfonylurea H 0.54–0.93 1.80–3.11Monocrotophos UPLC–MS/MS Methanol Organophosphorous A, I 0.87–0.96 2.91–3.17Monolinuron UPLC–MS/MS Methanol/Acetonitrile Urea H 0.25–0.38 0.84–1.27Neburon UPLC–MS/MS Acetonitril Urea H 0.74–2.97 2.47–9.92Oxadixyl UPLC–MS/MS Methanol/Acetonitrile Phenylamide F 0.29–1.68 0.97–5.61Oxamyl UPLC–MS/MS Methanol/Acetonitrile Oxime carbamate A, I, N 2.14–2.97 7.15–9.92Oxyfluorfen UPLC–MS/MS Methanol/Acetonitrile Diphenyl ether H 2.67–3.01 8.92–10.05Penconazole UPLC–MS/MS Methanol/Acetonitrile Triazole F 0.68–1.53 2.27–5.11Pendimethanil UPLC–MS/MS Methanol/Acetonitrile Dinitroaniline H 0.47–1.58 1.57–5.28Phenthoate UPLC–MS/MS Methanol Organophosphorous A, I 0.67–1.56 2.24–5.21Phosalone UPLC–MS/MS Methanol/Acetonitrile Organophosphorous A, I 1.26–1.57 4.21–5.24Phosmet UPLC–MS/MS Methanol/Acetonitrile Organophosphorous A, I 0.29–0.84 0.97–2.81Piperonyl UPLC–MS/MS Acetonitril Unclassified S 1.25–1.81 4.18–6.05Pirimicarb UPLC–MS/MS Methanol/Acetonitrile Carbamate I 0.56–0.84 1.87–2.81Pirimiphos methyl UPLC–MS/MS Acetonitril Organophosphorous A, I 0.33–0.74 1.1–2.47Prochloraz UPLC–MS/MS Acetonitril Imidazole F 0.64–1.25 2.14–4.18Profenofos UPLC–MS/MS Acetonitril Organophosphorous A, I 0.37–1.54 1.24–5.14Propargite UPLC–MS/MS Acetonitril Unclassified A 0.67–0.85 2.24–2.84Propiconazole UPLC–MS/MS Acetonitril Triazole F 1.02–1.58 3.41–5.28

382 G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392

Propyzamide UPLC–MS/MS Acetonitril Benzamide H 0.87–1.64 2.91–5.48Pymetrozine UPLC–MS/MS Acetonitril Pyridine I 0.69–2.96 2.31–9.89Pyraflufen-ethyl UPLC–MS/MS Acetonitril Phenylpyrazole H 0.52–2.58 1.74–8.62Pyrazophos UPLC–MS/MS Acetonitril Phosphorothiolate F 0.37–1.24 1.24–4.14Pyridaben UPLC–MS/MS Methanol/Acetonitrile Unclassified A, I 0.58–0.84 1.94–2.81Pyridaphenthion UPLC–MS/MS Methanol/Acetonitrile Organophosphorous A, I 0.39–0.57 1.30–1.90Pyridate UPLC–MS/MS Acetonitril Phenylpyridazine H 0.69–1.25 2.31–4.18Pyrimethanil UPLC–MS/MS Methanol/Acetonitrile Anilinopyrimidine F 0.53–1.67 1.77–5.58Pyriproxyfen UPLC–MS/MS Acetonitril Juvenile hormon mimic I 0.81–1.22 2.71–4.01Quizalofop-p-ethyl UPLC–MS/MS Acetonitril Unclassified H 0.37–1.24 1.24–4.15Resmethrin UPLC–MS/MS Methanol Pyrethroid I 0.67–0.85 2.24–2.84Simazine UPLC–MS/MS Methanol/Acetonitrile Triazine H 0.27–2.25 0.90–7.52Spinosad A, D UPLC–MS/MS Acetonitril Spinosyn I 0.42–1.83 1.40–6.11Spirodiclofen UPLC–MS/MS Acetonitril Tetronic acid A, I 0.37–2.05 1.24–6.85Tebuconazole UPLC–MS/MS Methanol/Acetonitrile Triazole F 0.85–2.35 2.84–7.85Tebufenpyrad UPLC–MS/MS Acetonitril Pyrazole A 0.67–2.41 2.24–8.05Terbutryn UPLC–MS/MS Methanol/Acetonitrile Triazine H 0.59–2.22 1.97–7.42Thiabendazole UPLC–MS/MS Methanol Benzimidazole F 0.34–0.81 1.14–2.71Thiamethoxam UPLC–MS/MS Acetonitril Neonicotinoid I 0.26–1.25 0.87–4.18Thidiazuron UPLC–MS/MS Acetonitril Phenylurea PR 0.34–2.11 1.14–7.05Thifensulfuron-methyl UPLC–MS/MS Acetonitril Sulfonylurea H 0.68–1.15 2.27–3.84Thiodiocarb UPLC–MS/MS Acetonitril Oxime carbamate I, M 0.96–1.63 3.21–5.44Thiophonate-methyl UPLC–MS/MS Methanol/Acetonitrile Benzimidazole F 0.65–1.57 2.17–5.24Tolyfluanide UPLC–MS/MS Methanol Sulphamide F 0.49–0.93 1.64–3.11Triadimefon UPLC–MS/MS Acetonitril Triazole F 0.37–1.61 1.24–5.38Triadimenol UPLC–MS/MS Methanol/Acetonitrile Triazole F 0.75–0.96 2.51–3.21Triallate UPLC–MS/MS Methanol Thiocarbamate H 0.81–1.27 2.71–4.24Triasulfuron UPLC–MS/MS Acetonitril Sulfonylurea H 1.36–1.58 4.54–5.28Tribenuron-methyl UPLC–MS/MS Acetonitril Triazinylsulfonylurea H 2.25–2.67 7.52–8.92Trichlorfon UPLC–MS/MS Methanol Organophosphorous I 0.91–1.85 3.04–6.18Tridemorph UPLC–MS/MS Acetonitril Morpholine F 0.74–1.79 2.47–5.98Trifloxystrobin UPLC–MS/MS Methanol/Acetonitrile Trobilurin F 0.51–1.12 1.70–3.74Triflumizole UPLC–MS/MS Methanol Imidazole F 0.64–0.78 2.14–2.61Triticonazole UPLC–MS/MS Methanol Triazole F 1.02–3.15 3.41–10.52

a A: Acaricide, I: Insecticide, N: Nematicide, H: Herbicide, F: Fungiside, M: Molluscicide, S: Synergist.b LOD range and LOQ range for 186 pesticides in fruits and vegetables matrices (lg kg�1).

Table 2Number of samples.

Name of the fruitsamples

No. of thesamples

Name of thevegetables samples

No. of thesamples

Apples 93 Arugula 20Apricot 20 Aubergine 43Banana 28 Bean 30Carrot 36 Cabbage 32Cherry 22 Cauliflower 34Grape 87 Cucumber 69Kiwifruits 22 Leek 22Lemon 39 Lettuce 65Orange 37 Mushroom 81Peaches 40 Onion 66Pear 31 Pepper 83Plum 28 Potato 66Pomegranate 39 Purslane 38Strawberry 22 Tomato 177Tangerine 29 Zucchini 24

G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392 383

containing 100 mg PSA + 300 mg anh. MgSO4. For matrices thatcontain high amounts of carotene or chlorophyll, 50 mg of GCBwas added to the tubes. The extract was vortexed for 30 s and cen-trifuged again for 1 min at 1.6 rcf. An aliquot of the extract wastransferred to GC and LC vials. For LC–MS/MS analysis the extractswere diluted by 10% MeOH in water into vial (250 ll volume of ex-tract in 1 ml 10% MeOH).

2.6. Recovery, precision and detection limits

For the determination of recovery, precision and detection lim-its, pesticide free samples (blank samples) were used. The extrac-tion methods used had previously been validated by Lehotay(2007) because verification, which consists of recovery, precision

and detection limits, were conducted by analysing tomato, apples,peppers and lemon matrices as representative matrices for fruitsand vegetables. Samples were augmented five times at 0.05 and0.1 mg kg�1. The detection limit, which was derived from the anal-ysis of 10 independent sample blanks fortified at lowest concentra-tion that gave acceptable recoveries (between 70% and 120%) andprecision (R.S.D. Lower than 20%), were determined for each sam-ple (Bakirci & Hisil, 2011).

3. Results and discussion

3.1. Verification of analytical procedure

The extraction procedure for the determination of pesticide res-idues is based on fruits and vegetables by acetonitrile extractionand partitioning with magnesium sulphate (Lehotay, 2007). Amatrix-matched calibration curve was used for in each group toprevent matrix effect. The performance of this analytical methodwas conducted to determine recovery, precision and detectionlimits. The recovery values ranged from 73% to 115%, and thecalculated RSDs were lower than 20% for all of the investigatedanalytes. The LOD and LOQ for 186 pesticides in fruit and vegetablematrices are provided in Table 1. As observed from the table, theLOD and LOQ values were below 0.01 mg kg�1 for all analysedpesticides.

3.2. Survey data

For this survey, 186 pesticides belonging to different chemicalclasses, including insecticides and fungicides, were consideredamong those commonly used in different stages of production forfruits and vegetables in Turkey. A total of 43 pesticides were

384 G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392

analysed by GC–ECD and GC–MS, and the others were analysed byLC–MS/MS.

In this study, a total of 1423 samples were analysed for pesti-cide residue. A yearly total of 478, 441 and 504 of these sampleswere analysed in 2010, 2011, and 2012, respectively. Of the total,573 of the samples were fruits, and 850 were vegetables. All sam-ples of pomegranate, cauliflower and cabbage were pesticide-free.The results of the survey are presented in Tables 3 and 4. Table 3shows a summary of the pesticides found in fruits, and Table 4

Table 3Summary of the pesticides found in fruits.

Matrix No. of samples detectableresidues (%)

No. of samples >MRL(%)

Pesticides

Apples 64 (69) 2 (2.2) AcetamipriBromopropCarbarylCarbendazbenomylChlorpyripClofentezinCypermethDeltamethDimethoatFenpropathHexythiazoImazalilImidacloprIndoxacarbLambda-CyPhosalonePirimicarbPropargitePyridabenPyrimethanSpirodiclofTebufenpyThiabendaThiamethoThiophonaTrifloxystro

Apricot 9 (45) – AcetamipriCarbendazbenomylChlorpyripCypermethCyprodinilHexythiazoImidacloprPhosalonePyriproxyfTrifloxystro

Banana 17 (61) 1 (3.6) BifenthrinCarbendazbenomylChlorpyripImazalilThiabenda

Carrot 15 (42) – ChlorpyripTebuconazTrifluralin

Cherry 16 (73) 2 (9) CarbendazbenomylChlorpyripCypermethDiazinonDifenaconaHexythiazoPhosaloneThiophona

Grape 72 (83) 18 (21) AcetamipriAzoxystrobBoscalidCarbendaz

shows the summary of pesticide occurrence in vegetables.Detectable residues were found in 342 (60%) fruits and 412 (49%)vegetables samples at or below MRLs established by Turkish Regu-lation. Of all the samples, apples, grapes, cherry, pear, oranges, andtangerines for fruits and tomato, pepper, mushroom, lettuce, andcucumber for vegetables contained more residues than the others.

In all the analysed samples, 80 different pesticides were de-tected. The pesticide residues found most frequently were acetam-iprid, chlorpyriphos, azoxystrobin, boscalid, carbendazim,

found Frequency ofdetection

Range min–max(mg kg�1)

No. of samples>MRL

d 7 0.018–0.08ylate 1 0.13

1 0.16im/ 4 0.02–0.09

hos 13 0.01–0.074e 1 0.019rin 7 0.02–0.34rin 1 0.01e 1 0.02rin 1 0.06x 7 0.01–0.04 1

7 0.01–0.06id 2 0.030–0.037

1 0.011halothrin 4 0.019–0.08

28 0.01–1.59 11 0.0365 0.02–1.655 0.012–0.03

il 1 0.012en 1 0.03rad 4 0.01–0.04zole 12 0.02–2.35xam 1 0.043te methyl 1 0.022bin 2 0.01–0.02

d 3 0.012–0.050im/ 2 0.04–0.1

hos 1 0.025rin 5 0.037–0.066

1 0.061x 1 0.049id 1 0.01

3 0.04–0.128en 1 0.012

bin 2 0.011–0.0181 0.016

im/ 1 0.63 1

hos 4 0.01–0.028 0.03–0.18

zole 10 0.01–0.374hos 5 0.013–0.089ole 6 0.011–0.089

8 0.012–0.065im/ 5 0.011–0.068

hos 1 0.148rin 9 0.01–2.09 2

1 0.02 1zole 1 0.015x 1 0.114

4 0.01–0.19te methyl 6 0.010–0.036d 1 0.037in 25 0.01–2.97 1

17 0.02–1.676 3im/ 9 0.03–0.215

Table 3 (continued)

Matrix No. of samples detectableresidues (%)

No. of samples >MRL(%)

Pesticides found Frequency ofdetection

Range min–max(mg kg�1)

No. of samples>MRL

benomylChlorpyriphos 20 0.012–0.35Cypermethrin 5 0.013–0.246Cyprodinil 20 0.03–0.829 2Deltamethrin 1 0.078Dimethomorph 9 0.029–0.572 3Famaxadone 2 0.078–0.089Fenarimol 1 0.049Fludioxonil 18 0.014–0.924Flufenoxuron 12 0.01–0.53 2Hexythiazox 3 0.01–0.07 2Imazalil 4 0.03–0.371 3Imidacloprid 5 0.013–0.764Indoxacarb 16 0.01–0.764Kresoxim-methyl 2 0.026–0.22Lambda cyhalothrin 12 0.01–0.134Metalaxyl/Metalaxyl M

10 0.011–0.162

Methomyl 7 0.011–1.420 6Penconazole 11 0.01–0.341 1Procymidone 5 0.04–2.25Propargite 11 0.01–0.560Pyrimethanil 19 0.013–4.16Thiophonate methyl 4 0.031–0.311 2Triadimenol 25 0.012–1.27Trifloxystrobin 4 0.01–0.09

Kiwifruits 5 (22.7) – Carbendazim/benomyl

1 0.03

Chlorpyriphos 4 0.01–0.43Phosmet 1 0.04

Lemon 28 (72) 10 (26) 2.4-D 1 0.05Acetamiprid 1 0.01Bromopropylate 6 0.047–4.01 3Carbendazim/benomyl

6 0.014–0.334

Chlorpyriphos 13 0.01–0.16Hexythiazox 2 0.01–0.014Imazalil 7 0.241–6.79 2Pyridaben 6 0.012–0.019Pyrimethanil 3 0.027–0.45Pyriproxyfen 6 0.01–0.046Tebuconazole 6 0.12–0.95 6Thiabendazole 7 0.01–2.82

Orange 29 (78) 4 (11) Acetamiprid 1 0.022Bromopropylate 1 0.38Buprofezine 1 0.05Carbendazim/benomyl

3 0.01–0.124

Chlorpyriphos 18 0.01–0.14Dimethomorph 7 0.017–0.048Imazalil 7 0.012–1.30Malathion 2 0.03–0.08Procymidone 5 0.01–0.04 4Propargite 1 0.01Pyriproxyfen 3 0.01–0.02Tebuconazole 2 0.01–0.85 1Thiabendazole 9 0.01–1.23

Peaches 20 (50) 3 (7.5) Acetamiprid 6 0.02–0.183 2Boscalid 2 0.023–0.139Carbaryl 1 0.046Carbendazim/benomyl

3 0.024–0.151

Chlorpyriphos 5 0.01–0.029Cypermethrin 4 0.122–0.73Hexythiazox 1 0.046Penconazole 1 0.01Phosalone 1 0.024Phosmet 1 0.194 1Propargite 2 0.01–0.034Pyridaben 1 0.077 1Pyriproxyfen 6 0.01–0.14Tetradifon 1 0.03Thiophonate methyl 2 0.045–0.08Trifloxystrobin 1 0.053

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G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392 385

Table 3 (continued)

Matrix No. of samples detectableresidues (%)

No. of samples >MRL(%)

Pesticides found Frequency ofdetection

Range min–max(mg kg�1)

No. of samples>MRL

Pear 22 (71) 3 (9.7) Acetamiprid 1 0.06Boscalid 1 0.012Carbendazim/benomyl

1 0.235 1

Chlorpyriphos 4 0.01–0.246Cypermethrin 3 0.031–0.576Cyprodinil 1 0.038Difenoconazole 5 0.01–0.034Fenpropathrin 1 0.175Imidacloprid 10 0.01–0.54 2Lambda cyhalothrin 6 0.01–0.47 2Phosalone 2 0.03–0.04Tebuconazole 1 0.016Thiophonate methyl 1 0.074

Plum 7 (25) 2 (7) Acetamiprid 1 0.038 1Chlorpyriphos 2 0.046–0.122Cypermethrin 1 0.85 1Indoxacarb 1 0.017Phosalone 2 0.08–0.099Propargite 1 0.279

Strawberry 14 (64) 2 (9) Acetamiprid 1 0.05 1Boscalid 1 0.014Bupirimate 1 0.046Carbendazim/benomyl

1 0.02

Carbofuran 1 0.01Chlorpyriphos 1 0.02Clofentezine 1 0.0128Cyprodinil 2 0.02–0.03Dichlorvos 1 0.08 1Difenoconazole 1 0.01Fludioxonil 2 0.03–0.05Hexythiazox 6 0.02–0.066Imidacloprid 1 0.1Kresoxim methyl 1 0.016Lufenuron 1 0.01Penconazole 2 0.01–0.033Procymidone 2 0.02–0.07Propargite 1 0.0104Pyrimethanil 2 0.058–0.08Pyriproxyfen 1 0.0188Spinosad A + D 2 0.029–0.038Triadimenol 1 0.025Trifloxystrobin 2 0.01–0.1

Tangerine 24 (83) 1 (3.5) Acetamiprid 1 0.017Azoxystrobin 3 0.01Buprofezine 1 0.012Chlorpyriphos 10 0.01–0.226Dimethomorph 9 0.019–0.062 1Imazalil 7 0.933–2.47Malathion 6 0.030–1.01Propiconazole 1 0.01Pyriproxyfen 7 0.01–0.065

386 G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392

cypermethrin, cyprodinil, dimethomorph, fludioxonil, imazalil,imidacloprid, lambda cyhalothrin, metalaxyl, methomyl, phos-alone, propargite, pyridaben, pyrimethanil, pyriproxyfen, thiaben-dazole and triadimenol. The frequency of the most detectedpesticides in fruits and vegetables are shown in Fig. 1. As the graphindicates, acetamiprid is one of the main detectable residue forvegetables and occurred in the concentration range of 0.01–0.86mg kg�1, and chlorpyriphos is one of the main detectable residuesfor fruits and occurred in the concentration range of 0.01–0.35mg kg�1. Residues of acetamiprid were at a maximum in lettuce,tomato and pepper, while chlorpyriphos, pyrimethanil, cyprodinil,and fludioxonil were highest in grapes. Chlorpyriphos was alsowidely detected in apples, oranges, tangerines and lemons.

Azoxystrobin was mostly used in grapes and tomatoes, boscalidwas mostly used in pepper, tomato and grape, carbendazim/benomyl was mostly used in mushrooms and tomatoes, imidaclo-

prid was mostly used in pepper, lettuce and pears, metalaxyl andmethomyl were mostly used in cucumber, thiabendazole wasmostly used in apples and bananas, and triadimenol was mostlyused in peppers, grapes and tomatoes. Phosalone was widely pres-ent in apples because of the worm inside of the apples rangingfrom 0.01 to 1.59 mg kg�1. Among the mostly detected pesticideresidues, imazalil was found at the highest concentration(6.79 mg kg�1) in lemon.

The results were evaluated according to the MRLs that havebeen established by Turkish regulation. According to our results,48 (8.4%) of the fruit samples and 83 (9.8%) of the vegetable sam-ples contained pesticide residues above MRLs. MRL values weremost often exceeded in arugula, cucumber, lemon, and grape com-modities. All pesticides detected in apricot, carrot, kiwifruit andleek were below the MRLs. The results showed that carbenda-zim/benomyl was found in mushroom at a range of 0.012–3.53

Table 4Summary of the pesticides found in vegetables.

Matrix No. of samples detectableresidues (%)

No. of samples >MRL(%)

Pesticides found Frequency ofdetection

Range min–max(mg kg�1)

No. of samples>MRL

Arugula 11 (55) 9 (45) Acetamiprid 1 0.102Boscalid 1 0.603Carbendazim/benomyl

1 0.01

Chlorpyriphos 7 0.05–2.55 7Cypermethrin 2 0.23–1.84Dimethoate 2 0.06Imidacloprid 1 0.01Lambda cyhalothrin 2 0.096–0.123Metalaxyl/MetalaxylM

6 0.017–0.8

Methomyl 4 0.02–4.39 3Metribuzine 1 0.064Oxamyl 1 0.014Propargite 1 0.76Pyridaben 1 0.01Thiamethoxam 1 0.03Trifluralin 1 0.485

Aubergine 26 (61) 3 (7) Acetamiprid 11 0.018–0.23 1Azoxystrobin 4 0.01–0.059Boscalid 3 0.018–0.062Carbendazim/benomyl

3 0.02–0.05

Chlorpyriphos 1 0.015Cyprodinil 5 0.01–0.06Epoxiconazole 1 0.02Fludioxonil 3 0.01–0.06Imidacloprid 1 0.06Kresoxim methyl 1 0.055Methomyl 3 0.012–0.456 3Pirimicarb 1 0.031Propargite 3 0.01–0.07Pyridaben 1 0.01Pyrimethanil 1 0.014Spinosad A + D 3 0.029–0.053Triadimenol 3 0.02–0.08Trifloxystrobin 1 0.04

Bean 15 (50) 3 (10) Acetamiprid 1 0.01Alpha endosulfan 1 0.01Azoxystrobin 1 0.06Boscalid 1 0.283Carbendazim/benomyl

5 0.016–0.062

Chlorpyriphos 1 0.047Cyprodinil 1 0.03Dimethomorph 1 0.057 1Fludioxonil 1 0.021Hexythiazox 2 0.029–0.07Metalaxyl/MetalaxylM

2 0.012–0.014

Methomyl 2 0.016–0.042 1Penconazole 1 0.042Procymidone 3 0.04–0.6Propargite 3 0.023–0.525 1Pyridaben 2 0.03–0.04Pyrimethanil 1 0.017Thiophonate methyl 1 0.012Triadimenol 1 0.06

Cucumber 49 (71) 18 (26) Acetamiprid 9 0.016–0.069Alpha endosulfan 2 0.04–0.11 1Azoxystrobin 4 0.02–0.1Beta endasulfan 2 0.03–0.12 1Boscalid 3 0.565 1Carbendazim/benomyl

6 0.02–0.172 4

Chlorpyriphos 1 0.052 1Cymoxanyl 5 0.014–0.110 3Dichlorvos 3 0.016–0.27 2Dimethomorph 9 0.01–0.199 8Famoxadone 2 0.021–0.06Hexythiazox 1 0.01Imidacloprid 2 0.028–0.09Iprodione 1 Oca.59

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G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392 387

Table 4 (continued)

Matrix No. of samples detectableresidues (%)

No. of samples >MRL(%)

Pesticides found Frequency ofdetection

Range min–max(mg kg�1)

No. of samples>MRL

Kresoxim methyl 1 0.015Malathion 1 0.02 1Metalaxyl/Metalaxyl-M

13 0.01–0.421

Methomyl 6 0.02–1.09 4Oxamyl 4 0.01–0.32 2Procymidone 1 0.02Propargite 1 0.01Pyridaben 2 0.01–0.03Spinosad A + D 1 0.031Tebuconazole 2 0.09–0.15Tebufenpyrad 1 0.02Thiamethoxam 1 0.023Triadimenol 1 0.08

Leek 2 (9) – Phenthoate 2 0.02–0.03Lettuce 29 (45) 6 (9.2) Acetamiprid 10 0.01–0.86

Alpha endosulfan 1 0.02Boscalid 8 0.013–0.198Bromopropylate 1 0.06Carbendazim/benomyl

1 0.21 1

Chlorpyriphos 4 0.01–0.021Cypermethrin 3 0.123–1.730Dimethomorph 1 0.012Famoxadone 1 0.128 1Hexythiazox 1 0.02Imazalil 1 0.011Imidacloprid 11 0.03–0.46Lufenuron 1 0.12Metalaxyl/MetalaxylM

1 0.018

Methomyl 4 0.013–2.75 3Penconazole 1 0.017Procymidone 2 0.014–0.72 1Thiomethoxam 7 0.011–0.293Trifloxystrobin 2 0.016–0.058 1

Mushroom 58 (72) 13 (16) Acetamiprid 1 0.017 1Alpha endosulfan 2 0.02–0.16 1Beta endosulfan 2 0.01–0.08 1Carbendazim/benomyl

51 0.012–3.53 8

Chlorfluazuron 1 0.01Chlorpyriphos 1 0.01Cypermethrin 1 0.01Diazinon 5 0.01–0.08Dimethoate 1 0.078 1Endosulfan sulfate 1 0.05Hexythiazox 1 0.075Methomyl 2 0.818–2.13 2Pyriproxyfen 1 0.01Tebuconazole 1 0.03Thiabendazole 1 0.01

Onion 21 (32) 2 (3) Carbaryl 1 0.305Cypermethrin 2 0.086–0.201 1Imidacloprid 1 0.072Lamda Cyhalothrin 1 0.222 1Methomyl 1 0.036 1Oxadixyl 1 0.013Phenthoate 16 0.01–0.108Pyridaben 1 0.01Pyriproxyfen 1 0.01

Pepper 59 (71) 8 (9.6) Acetamiprid 29 0.01–0.79 2Alpha endosulfan 2 0.23–0.43Azoxystrobin 6 0.02–0.34Beta endosulfan 2 0.56–0.70Boscalid 14 0.03–0.724Bromopropylate 1 0.234Buprofezine 6 0.01–0.075Carbendazim/benomyl

8 0.011–0.21 2

Chlorfluazuron 2 0.01–0.018Chlorpyriphos 3 0.01–0.406

388 G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392

Table 4 (continued)

Matrix No. of samples detectableresidues (%)

No. of samples >MRL(%)

Pesticides found Frequency ofdetection

Range min–max(mg kg�1)

No. of samples>MRL

Clofentezine 5 0.01–0.086 3Cyprodinil 6 0.01–0.061Deltamethrin 2 0.012–0.022Difenoconazole 1 0.01Dimethomorph 1 0.07 1Fludioxinil 5 0.022–0.55Hexythiazox 2 0.01–0.16Imidacloprid 14 0.01–1.24 1Kresoxim methyl 3 0.02–0.04Malathion 2 0.012–0.08Metalaxyl/MetalaxylM

2 0.03–0.180

Methomyl 4 0.02–0.415 2Myclobutanil 1 0.38Oxamyl 1 0.03 1Penconazole 7 0.01–0.08Pirimiphos methyl 2 0.088–0169Procymidone 4 0.039–0.28Propargite 1 0.017Pyridaben 9 0.01–0.087Pyrimethanil 2 0.01–0.03Pyriproxyfen 8 0.01–0.056Spinosad A + D 5 0.023–1.256Tebuconazole 1 0.01Thiamethoxam 1 0.016Triadimenol 10 0.02–0.18Trifloxystrobin 1 0.02 1Triflumizole 1 0.03

Potato 11 (17) 3 (4.5) Chlorpyriphos 1 0.02Imidacloprid 3 0.011–0.043 1Metalaxyl/metalaxylM

5 0.01–0.062 1

Oxadixyl 4 0.02–0.079 1Pyiproxyfen 1 0.01Quinomethionate 1 0.01

Purslane 5 (13) 3 (8) Acetamiprid 3 0.028–0.08 2Imidacloprid 1 0.059 1Propargite 1 0.012 1

Tomato 118 (67) 14 (8) Acetamiprid 58 0.01–0.29 9Azoxystrobin 13 0.01–0.19Boscalid 12 0.013–0.117Bromopropylate 3 0.029–0.1Buprofezine 1 0.03Carbendazim/benomyl

12 0.02–1.2 1

Chlorothalonil 1 0.81Chlorpyriphos 5 0.01–0.053Clofentezine 1 0.014Cyprodinil 7 0.01–0.17Dimethomorph 5 0.01–0.114Famoxadone 8 0.02–0.091Fenazaquin 1 0.01Fludioxonil 9 0.01–0.10Hexythiazox 2 0.01Imazalil 1 0.02Imidacloprid 9 0.012–0.088Indoxacarb 4 0.012–0.038Iprodione 1 0.69Metalaxyl/Metalaxyl-M

5 0.01–0.05

Oxadixyl 1 0.011Oxamyl 3 0.01–0.09 2Penconazole 1 0.01Pendimethalin 1 0.012Procymidone 4 0.01–0.16Propargite 3 0.01–0.06Pymetrozine 2 0.045–0.38Pyridaben 26 0.01–0.39Pyrimethanil 6 0.01–0.12Pyriproxyfen 8 0.01–0.36Spinosad A + D 2 0.01–0.014Tebuconazole 6 0.02–0.27 6

(continued on next page)

G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392 389

Fig. 1. The frequency of the most commonly detected pesticides in fruits and vegetables.

Fig. 2. The percentage of pesticide residues exceeding the MRLs between 2010 and 2012.

Table 4 (continued)

Matrix No. of samples detectableresidues (%)

No. of samples >MRL(%)

Pesticides found Frequency ofdetection

Range min–max(mg kg�1)

No. of samples>MRL

Triadimenol 13 0.01–0.59 1Trifloxystrobin 3 0.01–0.03

Zucchini 8 (33) 1 (4) Acetamiprid 5 0.02–0.241Boscalid 2 0.026–0.09Chlorpyriphos 1 0.57 1Dimethomorph 1 0.012Kresoxim-methyl 2 0.01–0.03Trifloxystrobin 1 0.04

390 G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392

mg kg�1, which exceeded the MRLs. Chlorpyriphos exceeded theMRLs in arugula at levels ranging from 0.05 to 2.55 mg kg�1, whiledimethomorph exceeded the MRLs in cucumber at concentrationsfrom 0.01 to 0.199 mg kg�1. Additionally, acetamiprid residues

were present most frequently in tomato in the range of 0.01–0.29 mg kg�1, which most often exceeded the MRLs. Methomyl ex-ceeded the MRLs in grapes and varied from 0.011–1.420 mg kg�1.Although mushroom and the grapes contained the highest pesti-

G.T. Bakırcı et al. / Food Chemistry 160 (2014) 379–392 391

cide residues of all samples, only 13 samples and 18 samples ex-ceeded the MRL values, respectively.

For the co-occurrence of pesticide residues, 285 samples con-tained more than one pesticide residue. A total of 116 samples con-tained four or more pesticide residues. Grape, cucumber, pepperand tomato samples were especially prone to co-occurrence andcontained four or more pesticide residues.

In our study, 68 (14%) of the samples in 2010 exceeded theMRLs, whereas in 2011, 42 (10%) of samples exceeded the MRLs.In 2012, only 21 (4%) samples exceeded the MRLs (Fig. 2). The re-sults indicate that the percentage of the samples exceeding MRLvalues decreased over the three years of this study. This declinecould be dependent on tighter government regulation, which in-cluded increased education of farmers, control of pesticide sales,and improvement of organic agriculture and implementation ofintegrated pest management methods.

Among all samples, a total of 131 (9.2%) contained pesticide res-idues above MRLs. Similarly, Knezevic and Serdar (2009) analyseda total of 240 fresh fruit and vegetable samples from the Croationmarket. These researchers found that 7.5% of the samples con-tained pesticide residues above MRLs. A separate project was con-ducted to investigate the pesticide residues in 46 different fruitsand vegetables from eight South American countries in 2007, and8.4% of samples analysed were found to be contaminated with pes-ticides above MRLs (Hjorth et al., 2011). Osman et al. (2010) re-ported that 53 of the 160 vegetable samples were above MRLs intheir study. On the contrary, a total of 13,556 samples of 22 fruitsand vegetables crops and rice and beans were analysed for thedetection of pesticide residues in Brazil from 2001 to 2010, Jardimand Caldas (2012) indicated that less than 3% of these samples hadresidue levels above the MRL. However, 13.2% of the samples pre-sented an irregularity (mostly non-authorised active ingredientuse). In this study, none of the samples contained non-authorisedpesticide active substances.

According to our results, the contamination levels of pesticideresidues could not be perceived as a serious problem because ofthe most of pesticide residue values, which exceeded the MRLSwere only a little bit more than the MRLs. And also incidence ofpesticides that exceeded the MRLs detected in vegetables washigher than those in fruits, and most vegetables are consumed aftercooking, except arugula, cucumber and lettuce, while tomato,purslane, pepper, onion and leek can be consumed either raw orcooked. Certain operations, such as storage, washing, peeling andcooking, lead to a large reduction of pesticide residues (Kaushik,Satya, & Naik, 2009). For instance, a reduction of phosalone was ob-served during the washing process in apples; similarly, washing re-moved 75% of the azoxystrobin residues on grapes (Lentza-Rizos,Avramides, & Kokkinaki, 2006; Mergnat, Fritsch, Saint-Joly,Truchot, & Saint-Blankquat, 1995; Stepán, Tichá, Hajslova, Kovale-zuk, & Kocourek, 2005). Washing is the most common form of pro-cessing and is a preliminary step in both commercial andhousehold preparation. Peeling is also an effective process forreduction of pesticide residues. Additionally, cooking of food prod-ucts helps to eliminate most of the pesticide residues. Peeling fruitsand vegetables, such tomatoes, potatoes, avocado, bananas, citrus,kiwifruit, mango and pineapple, achieves virtually complete re-moval of residues from the fruit (González-Rodriguez, Rial-Otero,Cancho-Grande, Gonzalez-Barreiro, & Simal-Gándara, 2011;Kaushik et al., 2009). To determine the effectiveness of the reduc-tion of pesticides by these procedures, it is important to under-stand whether the procedure for pesticide removal is systemic.

4. Conclusions

1423 Samples, which included 573 fruits and 850 vegetables,were investigated for pesticide residues. For the first time, the re-

sults of the study provided important information regarding pesti-cide residues for fruits and vegetables from Turkey. According tothe results, the most detected pesticides were acetamiprid, carben-dazim and chlorpyriphos. In this study, the percentage of pesticideresidues exceeding the MRLs showed a decrease over a three-yearperiod. Based on this decline, it is concluded that tighter measures,such as education of farmers, control of the sale of pesticides andimprovement of the organic agriculture and implementation ofintegrated pest management methods, is necessary for the reduc-tion of pesticide residues in foods and prevention of exposure topesticides.

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