Yazar "Kabak, Bülent" seçeneğine göre listele

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    Determination of more than 500 Pesticide Residues in Hen Eggs by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) and Gas Chromatography-Tandem Mass Spectrometry (GC/MS/MS)
    (2021) Gölge, Özgür; Liman, Turan; Kabak, Bülent
    This study aims to validate a fast method of simultaneous analysis of 365 LC-amenable and 142 GC-amenable pesticides in hen eggs by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively, operating in multiple reaction monitoring (MRM) acquisition modes. The sample preparation was based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction. Key method performance parameters investigated were specificity, linearity, limit of quantification (LOQ), accuracy, precision and measurement uncertainty. The method was validated at two spiking levels (10 and 50 mu g/kg), and good recoveries (70%-120%) and relative standard deviations (RSDs) (<= 20) were achieved for 92.9% of LC-amenable and 86.6% of GC-amenable pesticide residues. The LOQs were <= 10 mu g/kg for 94.2% of LC-amenable and 92.3% of GC-amenable pesticides. The validated method was further applied to 100 egg samples from caged hens, and none of the pesticides was quantified.
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    Öğe
    Health risk assessment of selected pesticide residues in green pepper and cucumber
    (Pergamon-Elsevier Science Ltd, 2018) Gölge, Özgür; Hepsağ, Fatma; Kabak, Bülent
    This report describes levels of 170 pesticide residues in green pepper and cucumber marketed in Turkey. The report also comprises the outcome of the consumer risk assessment of selected pesticides. In total, 725 samples of vegetables were analysed for residues of 170 distinct pesticides by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The in-house validation data fulfilled the requirements of the European SANTE/11945/2015 Guideline. The limit of quantifications (LOQs) varied from 0.003 to 0.016 mg kg-1. Recoveries ranged between 80.5 and 118.2%, with inter-day precisions of 0.7-19% relative standard deviation (RSD). The expanded measurement uncertainty for individual pesticides ranged from 10.4 to 42.4%. Overall, 12.9% of green peppers and 13.5% of cucumbers contained at least one detectable residue, but the levels were below the EU legal limits. For adults, the Hazard Quotients (HQs) for identified pesticides in green peppers and cucumbers ranged from 0.0003 to 0.0143%, and from 0.0001 to 0.0103%, respectively. Propamocarb and chlorpyrifos were the major contributors to hazard index (HI) for green pepper and cucumber, respectively. The results showed that there is no reason to be concerned about cumulative exposure to residues from green pepper and cucumbers for Turkish population.
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    Öğe
    Occurrence of deoxynivalenol and zearalenone in cereals and cereal products from Turkey
    (Elsevier Sci Ltd, 2020) Gölge, Özgür; Kabak, Bülent
    This report describes concentrations of deoxynivalenol (DON) and zearalenone (ZEA) in cereals and derived products collected in Turkey from 2015 to 2018. A total of 240 cereals and cereal products were analysed by high performance liquid chromatography coupled with photodiode array (HPLC-PDA) and fluorescence (HPLC-FLD) detectors. The analytical method performance was satisfactory, with limit of quantification (LOQ) values of 46.90-72.30 mu g kg(-1), and 3.50-3.70 mu g kg(-1) for DON and ZEA, respectively. Thirteen wheat (58-1092 mu g kg(-1)), two maize (313-331 mu g kg(-1)), three barley (138-973 mu g kg(-1)), seven paddy rice (136-256 mu g kg(-1)), three wheat flour (92-151 mu g kg(-1)), two biscuits (31.2-71.3 mu g kg(-1)) and only one pasta (49.3 mu g kg(-1)) contained DON, but levels were below the EU maximum level (ML). DON was not detected in bulgur and wheat bread. ZEA was found in two wheat, three maize, eleven paddy rice and two wheat flour with a mean middle bound ZEA level of 1.34, 28.0, 42.9, and 2.66 mu g kg(-1), respectively. Amongst the samples contaminated with ZEA, only one paddy rice exceeded EU ML of 100 mu g kg(-1). However, barley, bulgur, wheat bread, pasta and biscuit products did not contain ZEA.
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    Öğe
    Pesticide residues in table grapes and exposure assessment
    (Amer Chemical Soc, 2018) Gölge, Özgür; Kabak, Bülent
    This report describes levels of 172 pesticide residues in table grapes in Turkey. A total of 280 samples of table grapes were collected from supermarkets, bazaar, and greengrocer shops located in four provinces of Turkey from August to October 2016. The samples were analyzed by liquid chromatography coupled to tandem mass spectrometry. The limit of quantification ranged from 0.002 to 0.010 mg kg(-1). The validation data revealed good recoveries and good repeatability and reproducibility and fulfilled the other requirements of the European SANTE/11945/2015 Guideline. One or more pesticide residues were detected in 59.6% of the table grapes. The residues above the EU maximum residue levels were 20.4% of the samples. The most prevalent pesticide residues were azoxystrobin, chlorpyrifos, boscalid, and cyprodinil. Left-censored results (40.4% of the results) were substituted by lower bound, middle bound, and upper bound values. In the worst-case scenario, the hazard index (HI) was 3.37% for adults and 9.42% for children. Chiorpyrifos was the major contributor (65%) to HI.
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    Öğe
    Quantification of pesticide residues in gherkins by liquid and gas chromatography coupled to tandem mass spectrometry
    (Academic Press Inc Elsevier Science, 2021) Gölge, Özgür; Cinpolat, Seren; Kabak, Bülent
    The monitoring of pesticide residues in fruits and vegetables is a great concern in public health and international trade. This study aims to assess the incidence and quantification of pesticides in gherkins cultivated in Turkey. The sample preparation was based on QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction. The residues were determined by in-house validated methods based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS). This study included 109 pesticide residues, of which 85 were analysed by LC-MS/MS, and 24 were analysed by GC-MS/MS. Key method performance parameters investigated were linearity, limit of quantification (LOQ), accuracy, precision and measurement uncertainty. The LOQs ranged from 0.002 to 0.005 mg kg(-1). Of the 203 gherkin samples analysed, 57.6 % were free from the detectable level of residues. In 42.4 % of the samples, 15 different residues were found in measurable levels, of which 5 were non-approved in EU. Multiple pesticide residues were recorded in 17.2 % of the samples. In 7.9 % of the gherkin samples, the residue levels exceeded the maximum residue levels (MRLs). Among the residues, chlorothalonil (detected in 32 % of the samples), acetamiprid (16.3 %) and metalaxyl (and its enantiomer metalaxyl-M) (4.9 %) were the most frequently quantified pesticides.