Pesticide residues in agricultural products monitored in Hyogo Prefecture,Japan, FYs 1995-1999

During a 5-year monitoring survey (April 1995-March 2000) of pesticide residues in agricultural products, 765 samples (478 domestic; 287 imported) collected in Hyogo Prefecture, Japan, were analyzed. The number of pesticides tested increased from 107 in fiscal year (FY) 1995 to 204 in FY 1999. The purpose of the study was to promote consumer safety by excluding the food illegally containing pesticide residues from markets. Overall, 51 % of domestic and 32% of imported samples contained no detectable residues. Multiple residues were detected in 152 (32%) of domestic and 146 (51%) of imported samples. The limit of quantitation was set at 0.01 microg/g and the limit of detection was 0.001 microg/g. Most of the residues were present at low concentrations; 70% of detections in domestic samples were <0.05 microg/g, and 97% were <0.5 microg/g. Although 86% of antifungal agent residues in imported citrus fruits were > or = 0.1 microg/g, 59% of the other residues in imported samples were <0.05 microg/g, and 96% were <0.5 microg/g. Violations of maximum residue limits (MRL) were observed in 3 samples: diazinon in chrysanthemums, dieldrin in cucumbers, and bitertanol in bananas. Of the detectable residues above 0.01 microg/g, 55% in domestic and 38% in imported samples were <10% of the MRL. Of all the samples, 2.4% contained more than 5 different pesticides; tomatoes, strawberries, apples, and citrus fruits tended to have more multiple residues.     

Monitoring of pesticide residues in Egyptian fruits and vegetables during 1996

Samples of the most common fruits and vegetables were collected from 8 local markets in 6 governorates. These 1,579 samples were analyzed for residues of 53 pesticides, which included organophosphorus and organonitrogen compounds and some synthetic pyrethroids. Samples were also analyzed for residues of organochlorine pesticides, although they had been prohibited from use several years ago. Only 510 of the 1,579 samples were analyzed for dithiocarbamate pesticide residues, which were determined as CS2. Overall, 76.1 % of the total analyzed samples had no detectable residues, 23.9% contained detectable residues, and 2.59% contained residues that exceeded maximum residue limits. For individual crops, contaminated samples ranged from 0 to 96% of the number of samples analyzed. However, the highest violative percentage for samples of individual crops was 12.5. Chlorpyrifos, carbaryl, dimethoate, bromopropylate, and profenofos were the violative pesticides determined in fruit and vegetable samples. The results of the current study demonstrated that no restricted or banned pesticides such as DDT, HCH, and their isomers were found in any of the samples analyzed. Dithiocarbamate residues were detected in 9.4% of the 510 samples analyzed, with a violative percentage of 0.39, representing one grape sample and one peach sample.     

Survey of low-level endocrine disrupting pesticides in food matrices in Slovakia

The search on endocrine disrupting chemicals (EDCs) in non-fatty food was evaluated. A fast, high-throughput, accurate, multiresidue method for the analysis of selected EDC pesticides in fruit and vegetable food samples was developed. The QuEChERS technique was used for sample preparation. Fast GC-MS was performed with a narrow-bore capillary column and a quadrupole benchtop detector with electron ionization (EI) and negative chemical ionization (NCI). A part of the work was devoted to the comparison of NCI versus EI approach concerning the sensitivity of detection and to the study of selectivity enhancement in NCI mode. Matrix-matched standard solutions were utilized for calibration. The methods validation was performed. Fortification studies at 1, 5, 10 and 250?µg?kg^?1 for 35 pesticides in EI mode and 0.1, 1, 5 and 250?µg?kg^?1 for 28 pesticides in NCI mode were performed. Average recoveries for each fortification level ranged from 70 to 110% with >80% of recoveries between 90 and 110%. Limits of quantification (LOQs) were established at 5?µg?kg^?1 for EI and at 1?µg?kg^?1 for NCI mode, which is lower than the lowest maximum residue level (MRL) value set by the European Commission in fruit and vegetables. The developed and validated fast GC-MS method was successfully applied to the search of EDC pesticides at ultratrace concentration level in real fruit and vegetable samples in Slovakia. Thirty-four samples of 20 different commodities were analyzed. Seven samples contained residues of three or more EDCs pesticides.     

Monitoring pesticide residues in Egyptian fruits and vegetables in 1995.

Organophosphorus, dithiocarbamates, and some synthetic pyrethroids pesticides, which are commonly used in Egypt for pest control, were monitored, as well as persistent organochlorines, which had been prohibited from use several years ago. Fruit and vegetable samples (397) were collected from 8 local markets and examined for 52 pesticides. Of all analyzed samples, 42.8% contained detectable residues, of which 1.76% exceeded their maximum residue limits (MRLs). The rates of contamination with the different pesticides were 0-86%. However, violation rates among contaminated products were very low, ranging from 0 to 4.6%. In general, organochlorine pesticide residues were not detected in most samples. Dithiocarbamate residues were found in 70.4% of 98 samples analyzed for dithiocarbamates, but only one grape sample had residues exceeding the MRL established by the Codex Committee on Pesticide Residues.     

Spectrophotometric Estimation of Carbaryl Residue in Some Home Garden Vegetables

Abstract

Residues of carbaryl (1-Naphthyl N-methly carbamate) were determined in the fruit and foliage of seven home garden vegetables by a spectrophotometric method. Residues at harvest averaged the following levels; cabbage (head, 0.0 ppm), cucumber (foliage 0.0 ppm; fruit, 0.05 ppm), garden bush beans (fruit, 0.0 ppm), Okra (foliage, 0.0 ppm; fruit, 0.01 ppm), pepper (foliage, 2.72 ppm; fruit, 0.9 ppm), squash (foliage, 6.55 ppm; fruit, 0.0 ppm), and tomato (foliage, 2.07 ppm; green fruit, 0.09 ppm; mature fruit, 0.03 opm). Foliage of the vegetables contained higher concentrations of the insecticide, in most cases, than did the fruits. Even with excessive applications, the carbaryl residues were found to be below the tolerance level established by EPA.     

液相色谱-四极杆/ 飞行时间质谱快速筛查与确证苹果、番茄和甘蓝中的281种农药残留

建立了苹果、番茄和甘蓝中281种农药残留的QuEChERS结合液相色谱-四极杆/飞行时间质谱(LC-Q-TOF/MS)快速筛查方法。方法采用1%醋酸乙腈提取样品,经丙基乙二胺(PSA)净化,LC-Q-TOF/MS测定。281种农药在苹果、番茄和甘蓝中3个添加水平下的回收率在70%～120%范围的比例分别为98.6%、99.3%和98.2%;回收率的相对标准偏差(RSD)均≤20%(n=5);在0.25～10倍最大残留限量(MRL)的含量范围内,线性相关系数r²≥0.99的农药比例分别为95.7%、96.1%和98.2%;检出限分别为0.03～4.47、0.01～4.49和0.02～3.61 μg/kg。本方法采用精确质量数据库和谱图库检索的方式,实现了不用农药标准品对照而完成对果蔬中农药残留的快速筛查,提高了定性鉴别的准确性。应用所建立的方法对30个市售果蔬样品进行筛查,共检出13种农药残留。其中,甘蓝中甲胺磷的含量超过了GB 2763-2012《食品安全国家标准\5食品中农药最大残留限量》和欧盟的MRL;番茄中鱼藤酮的含量超出欧盟的MRL。     

Properties and determination of pesticides in fruits and vegetables

The intensive development of agriculture means that more and more toxic organic and inorganic compounds are entering the environment. Because of their widespread use, stability, selective toxicity and bioaccumulation, pesticides are among the most toxic substances contaminating the environment. They are particularly dangerous in fruit and vegetables, by which people are exposed to them. It is therefore crucial to monitor pesticide residues in fruit and vegetables using all available analytical methods.We set out the problems in the determination of organonitrogen and organophosphorus pesticides in samples of fruit and vegetables, including the complexity and the diversity of matrices in biological materials, and the very low level of pesticides present, as a result of which target analytes have to be isolated and then enriched prior to final determination.We discuss the various stages in the determination of pesticide residues in fruit and vegetables. We present results from the literature in the context of Maximum Residue Levels (MRLs) of target pesticides in fruit and vegetable samples. We discuss the merits of the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) technique and two-dimensional gas chromatography.     

液相色谱-四极杆/ 飞行时间质谱快速筛查与确证苹果、番茄和甘蓝中的281种农药残留

建立了苹果、番茄和甘蓝中281种农药残留的QuEChERS结合液相色谱-四极杆/飞行时间质谱(LC-Q-TOF/MS)快速筛查方法。方法采用1%醋酸乙腈提取样品,经丙基乙二胺(PSA)净化,LC-Q-TOF/MS测定。281种农药在苹果、番茄和甘蓝中3个添加水平下的回收率在70%～120%范围的比例分别为98.6%、99.3%和98.2%;回收率的相对标准偏差(RSD)均≤20%(n=5);在0.25～10倍最大残留限量(MRL)的含量范围内,线性相关系数r²≥0.99的农药比例分别为95.7%、96.1%和98.2%;检出限分别为0.03～4.47、0.01～4.49和0.02～3.61 μg/kg。本方法采用精确质量数据库和谱图库检索的方式,实现了不用农药标准品对照而完成对果蔬中农药残留的快速筛查,提高了定性鉴别的准确性。应用所建立的方法对30个市售果蔬样品进行筛查,共检出13种农药残留。其中,甘蓝中甲胺磷的含量超过了GB 2763-2012《食品安全国家标准\5食品中农药最大残留限量》和欧盟的MRL;番茄中鱼藤酮的含量超出欧盟的MRL。     

Comparison of different extraction methods for the simultaneous determination of pesticide residues in kiwi fruit using gas chromatography-mass spectrometry

The methods of simultaneous extraction of iprodione, chlorpyrifos-methyl, EPN and endosulfan (with its metabolites) from kiwi fruit using accelerated solvent extraction (ASE), supercritical fluid extraction (SFE), and liquid-liquid extraction (LLE) were tested and compared in terms of their of limits of detection and quantification, as well as the highest pesticide recoveries with the lowest residues in the final extracts. The analysis was performed using gas chromatography-mass spectrometry in the selected ion monitoring mode. The proposed methods featured good sensitivity, pesticide quantification limits were low enough, and the precision (expressed as relative standard deviations) ranged from 0.56 to 7.17%. The recoveries obtained from ASE, SFE and LLE were 77.5-120, 71.9-109.1 and 75.6-127.1%, respectively. The proposed methods were successfully applied for the monitoring of the selected pesticide residues in kiwi fruit samples collected from Jollanamdo area, Republic of Korea. Iprodione was detected at a level lower than the maximum residue limit (MRL) established by the Korea Food and Drug Administration (5 ppm), while EPN was detected at a level higher than the Korea Food and Drug Administration MRL (0.1 ppm) in the real samples. The proposed sample preparations led to a higher preconcentration of the pesticide fraction, and allowed the sensitive and selective determination of pesticides with varied physicochemical properties in kiwi fruit. Copyright (c) 2008 John Wiley & Sons, Ltd.     

高效液相色谱法同时测定蔬菜水果中的12种农药残留

建立了同时测定蔬菜水果中12种农药残留的反相高效液相色谱分析方法。将样品捣碎,用乙酸乙酯超声提取,经Florisil固相萃取柱净化、正己烷-二氯甲烷(体积比为1∶1)洗脱、氮气吹干、甲醇溶解并定容后,采用高效液相色谱柱分离、紫外检测,以外标法定量。结果表明：12种农药标准曲线的线性相关系数范围为0.9985~0.9999;检测限为0.14~2.65 ng;在水果中的平均加标回收率为62.2%~118.2%,相对标准偏差(RSD)为0.56%~11.8%;在蔬菜中的平均加标回收率为52.1%~124.6%,RSD为0.89%~18.4%。用所建立的方法成功地测定了白菜、莲白、黄瓜、苹果、梨等40份样品中的农药残留。方法具有快速、简便、准确、灵敏、重现性较好的特点,适合于蔬菜水果样品中多种微量农药残留的测定。     

Determination of five pesticide residues in oranges by matrix solid-phase dispersion and liquid chromatography to estimate daily intake of consumers.

Residues of benzoylphenylurea insecticides (diflubenzuron, hexaflumuron, and flufenuxuron), carboxamide acaricides (hexythiazox), and carbamate insecticides (benfuracarb) were determined in 150 orange fruit samples from September 1998 to June 1999, to estimate exposure of the Valencian population to oranges contaminated with these newly developed pesticides. The method for monitoring these residues is based on matrix solid-phase dispersion and liquid chromatography with UV or atmospheric pressure chemical ionization/mass spectrometry (APCI/MS) detection. Orange samples representing 11 varieties were collected from an agricultural cooperative and examined for the 5 pesticides. In 74.6% of all analyzed samples, the pesticide residues were below detection limits, which ranged from 0.002 to 0.05 mg/kg. Residues were detected in 25.4% of the samples, with higher incidences of diflubenzuron, flufenuxuron, hexythiazox, and benfuracarb; hexaflumuron residues were detected only occasionally. Two different pesticides exceeded maximum residue limits (MRLs) in 4 (2.7%) of the orange samples. Diflubenzuron surpassed 1 mg/kg MRL in 3 samples and flufenuxuron exceeded the 0.3 mg/kg MRL in 3 samples. The estimated daily intake of the 5 pesticide residues during the period was 0.077 microg/kg body weight per day. This value is much lower than the total admissible daily intake proposed by the Food and Agricultural Organization and the World Health Organization.     

The disappearance rate and risk assessment of thiacloprid residues in Asian pear using liquid chromatography confirmed with tandem mass spectrometry

This study was undertaken to quantify the residue levels and propose the dissipation kinetics of thiacloprid formulated as suspension concentrate in field‐incurred Asian pears grown under two different open‐field conditions. Samples were extracted with 20% distilled water in acetonitrile; partitioned with brine water and dichloromethane; and purified with a Florisil solid phase extraction cartridge. The analyte was identified with an LC ultraviolet detector, and field‐incurred samples were confirmed using LC–MS/MS. The calibration curve was linear over the range 0.05–5.0 mg/L with a satisfactory coefficient of determination (R ² = 0.9994). The limits of detection and limits of quantification (LOQ) were 0.003 and 0.01 mg/kg, respectively. The recovery rate fortified to blank samples at LOQ, 10× LOQ, and the maximum residue limit (MRL) were between 73.7 and 86.2% with relative standard deviation ≤9.0%. The residual concentrations at both sites were considerably lower than the MRL (0.7 mg/kg) set by the Korean Ministry of Food Drug Safety, with biological half‐lives of 5.0 and 7.4 days, for sites 1 and 2, respectively. From the pre‐harvest residue limit curve, it was predicted that if the residues were <1.13 or 1.40 mg/kg 10 days before harvest, the residue level would be lower than the MRL during harvest. Risk assessment on day 0 showed an acceptable daily intake (%) of 13.0% and 11.0% for sites 1 and site 2, respectively, which indicates that the residual amounts are not hazardous to the Korean population.     

Use patterns and residual levels of organophosphate pesticides on vegetables in Trinidad, West Indies.

The twin-island state of Trinidad and Tobago produces much of the fresh fruit and vegetables consumed locally, although some are exported to Europe and North America. On average, approximately 1500 tons of pesticides are imported annually, of which about 10-15% are organophosphates. A survey of local farmers revealed that a wide range of pesticides are used and that the same pesticides are used on several crops to control different pests. Application rates exceeding manufacturers' recommendations are also common, as is the disregard of recommended preharvest intervals after pesticide application. Praedial larceny and subsequent sale of freshly sprayed crops also contribute to the risks posed to consumers by pesticide residues. A market basket survey of produce conducted between October 1996 and May 1997 in Trinidad for organophosphate pesticides showed that 10% of produce exceeded the internationally acceptable maximum residue limits (MRLs) for the respective pesticides. Celery constituted 6.5% of all such samples, with over 83% of celery samples exceeding the MRL. Organophosphate pesticides detected were methamidophos, triazophos, prophenofos, diazinon, ethion, pirimiphos methyl, malathion, and dimethoate, with the first 4 being the most commonly detected. There is an urgent need for comprehensive monitoring and control of pesticides on produce by local regulatory agencies, especially because the above data relate only to one class of pesticides. The education of farmers on safe operating practices regarding pesticide application and observation of recommended preharvest intervals for applied pesticides is also required.     

Pesticide residue determination in vegetables from western China applying gas chromatography with mass spectrometry

In this study,an effort has been made to evaluate the pesticide residues in vegetables from western China. Fifty‐one pesticides, including organophosphorus, organochlorine, carbamate and pyrethroid, were detected in 369 commonly used vegetables by GC‐MS. Concentrations of organophosphorus pesticides were detected ranging from 0.0008 to 18.8200 mg/kg, among which organophosphorus pesticide concentrations exceeded their maximum residue levels (MRLs) in five samples. Carbamate and organochlorine pesticides were determined to have concentrations in the range of 0.0012–0.7928 mg/kg. The residual concentrations of carbamate pesticides in six samples and organochlorine pesticides in four samples exceeded their MRLs. The residual concentrations of five pyrethroid pesticides were within the range of 0.0016–6.0827 mg/kg and the pyrethroid residues in two samples exceeded their MRLs. The results revealed that pesticide residues in 70.73% of the vegetables samples were not detected, while in the rest of vegetables there were one or more pesticide residues and some even exceeded their MRLs, which would threaten the health of consumers. Our work provides significant information for the food safety regulations to control the excessive use of some pesticides on those kinds of vegetables from western China. Copyright © 2016 John Wiley & Sons, Ltd.     

超高效液相色谱-串联质谱法快速检测蔬菜中248种农药残留

采用超高效液相色谱-串联质谱（UHPLC-MS/MS）技术建立了快速检测蔬菜中248种农药残留的分析方法。蔬菜样品采用乙腈提取,盐析后无需净化,缩短了样品前处理的时间。采用正负离子多反应监测（MRM）模式对蔬菜中248种农药残留进行定性和定量分析。245种农药在各自的线性范围内线性关系良好（r>0.99）。除丁硫克百威、灭蝇胺、苯磺隆和二氯喹啉酸4种农药外,其余244种农药在3个添加水平下的平均回收率范围为63.0%～126.4%,相对标准偏差（RSD）范围为0.5%～26.7%,方法的定量限为0.001～0.030 mg/kg。该方法具有简单、快速、灵敏度高、准确度高等优点,适合蔬菜样品中农药多残留的快速检测分析。     

Screening Method for the Determination at Parts Per Trillion Levels of Pesticide Residues in Vegetables Combining Solid‐Phase Microextraction and Gas Chromatography‐Tandem Mass Spectrometry

Abstract

A new analytical method is proposed for determining residues of 70 pesticides of different chemical families at parts per trillion levels in fresh vegetables. For that, only 4 g of the vegetable samples were quickly extracted with 10 ml of ethyl acetate. The method is based on a vanguard/rearguard strategy that reduces the average time required per sample when the method is applied to a high number of vegetable samples in a quality control laboratory. At the beginning, an aliquot of the extract is evaporated and re‐dissolved in a mixture water:acetone (9∶1 v/v). For screening purposes, the pesticides were extracted for only 10 min by direct immersion of a solid‐phase microextraction (SPME) fiber (65 µm polydimethylsiloxane‐divinylbenzene, PDMS‐DVB). The SPME device was automated and on‐line coupled to a gas chromatograph with an ion trap mass spectrometer (GC‐MS) operated in full scan mode for screening in less than 18 min those samples that potentially contain pesticides above 0.01 mg kg^?1 (cut off value). After that, only those potentially non‐negative samples were reanalyzed by a sensitive quantifying/confirming method that re‐extract by SPME the pesticides in 55 min of absorption and determine them by GC with tandem MS (MS/MS). The method has been validated following EU guidelines and compared with a conventional extraction method based on the use of higher amounts of organic solvents. The limits of detection (LOD), confirmation (LOC) and quantitation (LOQ) as well as the calibration curves obtained allowed the determination of the target pesticides at concentrations clearly below the maximum residue levels (MRL) stated by EU being possible the determination of parts per trillion of the pesticides in ecological (green) vegetables. The method has been applied to the analysis of real samples and the results compared with those obtained by a conventional extraction method accredited by ENAC (Spanish Accreditation Body). The proposed method was also evaluated participating in a proficiency test with adequate results (z‐score among±2).     

Development of GC–MS/MS method for environmental monitoring of 49 pesticide residues in food commodities in Al-Rass,Al-Qassim region,Saudi Arabia

The harmful effects of pesticide residues are a threat to our health. Therefore, the current study aimed to validate a simple method for the determination of pesticide residues in commonly consumed fruits and vegetables from Al-Rass, Al-Qassim region, Saudi Arabia. A total of 1430 samples were collected from a local market and then analyzed for monitoring of 49 pesticide residues. A quick, easy, cheap, effective, rugged, and safe (QuEChERS) multi-residue extraction method followed by gas chromatography equipped with triple-quadrupole mass spectrometry (GC–MS/MS) was successfully implemented. This 17-min-run analytical method detects and quantifies pesticide residues with acceptable validation performance parameters in terms of sensitivity, selectivity, linearity, the limit of quantification, accuracy, and precision. The linear range of the calibration curves ranged from 10 to 300 µg/L, all the pesticide LODs ranged from 0.0005 to 0.0024 mg/kg, and the pesticide LOQs ranged from 0.0011 to 0.0047 mg/kg. The recovery values at the three fortification levels ranged from 78 % to 107 %, and the precision values (expressed as RSD%) were less than 20 % for all of the investigated analytes. The results showed that 138 (9.65 %) of the analyzed samples were contaminated with pesticide residues, 40 (2.80 %) of the analyzed samples exceeded the maximum residue limit (MRL) of the European Commission regulations (EC) for pesticides residues, 98 (6.85 %) of the analyzed samples were contaminated with residues below the MRL, and 1292 (90.35 %) of the analyzed samples were pesticide residue-free. Coriander contained the highest percentage (46.88 %) of pesticide residues, particularly tetradifon that representing 18.75 % noncompliance with the MRL, followed by parsley, with 20.59 % pesticide residues (10.29 % non-compliance). Multiple pesticide residues were observed most frequently in tomatoes and dates which were contaminated with buprofezin and ethion respectively.     

Kuwait's total diet study: dietary intake of organochlorine, carbamate, benzimidazole and phenylurea pesticide residues

The State of Kuwait in cooperation with the U.S. Food and Drug Administration (FDA) conducted a Total Diet Study (TDS) to estimate intakes of pesticide residues by the population. The levels of organochlorine (OC) pesticides, carbamates, benzimidazoles, and phenylureas in the TDS core list are reported here. The TDS core list was established through a national food consumption survey. All food items (140 for the Kuwaiti adult) were prepared as eaten and analyzed for the pesticides mentioned above. The FDA's multiresidue methods in Volume I of the Pesticide Analytical Manual were used in gas, liquid, and gel permeation chromatographic analyses. Only vegetable and fruit samples contained pesticide residues (mg/kg), including the carbamates 1-naphthol (1.4) and 3H-carbofuran (0.94) in carrots; the OC pesticide vinclozolin (0.47), 3H-carbofuran (0.66), and fenuron (0.6) in kiwi fruit; the OC pesticide procymidone (0.32) and carbendazim (0.5) in grapes; 3H-carbofuran (5.0) in apricots; the OC pesticides captan (0.013) and thiabendazole (0.63) in pears; captan (0.035) in plums; and carbendazim (0.4) in mandarin oranges. The levels of 3H-carbofuran found in both apricots and kiwi fruit exceeded the maximum residue limits (MRLs) of the Food and Agriculture Organization/World Health Organization (FAO/WHO) of the United Nations. The daily intakes of pesticides by the different population groups are discussed in light of the FAO/WHO acceptable daily intakes.     

Measurement of permethrin,deltamethrin and malathion pesticide residues in the wheat flour and breads and probabilistic health risk assessment: a case study in Kermanshah,Iran

ABSTRACT

This study was conducted to investigate the residues of pyrethroid and organophosphorus pesticide in flour and breads which were collected from local markets in Kermanshah province, Iran. Four different types of breads and two types of flour samples with high distribution were taken from market and their residues of pesticides were measured. A simple dispersive liquid–liquid microextraction (DLLME) method with solidification of floating organic drop was developed for the measurement. The health risk of these pesticides on adults and children health was assessed by target hazard quotient (THQ) using Monte Carlo simulation (MCS) method. About, 15% and 11.1% of total samples contained detectable levels of deltamethrin and malathion, respectively. None of the tested samples showed any permethrin residue. The results from all samples showed that none of the pesticides exceeded the maximum residue limits (MRLs). About 85% of pesticide residue detections were observed in tropical and mild weather area which is due to high consumption rate of insecticides in these areas. The percentile 95% of THQ is due to bread ingestion content of deltamethrin which was 0.033 and 0.070 for the adults and children, respectively, while this value for malathion was found to be, 0.015 and 0.030, respectively. In the adults and children for both deltamethrin and malathion, the percentile 95% of THQ value were lower than 1 (acceptable level). The non-carcinogenic health risk assessment indicated that bread consumers in Kermanshah province are not at a considerable risk because of deltamethrin and malathion.     

Multi-residue screening of pesticides in vegetables,fruits and baby food by stir bar sorptive extraction-thermal desorption-capillary gas chromatography-mass spectrometry

The performance of stir bar sorptive extraction (SBSE) for the enrichment of pesticides from vegetables, fruits and baby food samples is discussed. After extraction with methanol, an aliquot is diluted with water and SBSE is performed for 60 min. By applying a new thermal desorption unit (TDU), fully automated and unattended desorption of 98 stir bars is feasible, making SBSE very cost-effective. The presence of pesticide residues is elucidated with the retention time locked gas chromatography–mass spectroscopy method (RTL-capillary GC–MS). With SBSE–RTL-capillary GC–MS operated in the scan mode, more than 300 pesticides can be monitored in vegetables, fruits and baby food. The multi-residue method (MRM) described provides detectabilities from the mg/kg (ppm) to the sub-μg/kg (ppb) level, thereby complying with the maximum residue levels (MRLs) set by regulatory organizations for pesticides in different matrices. Several examples, i.e. pesticide residues in lettuce, pears, grapes and baby food, illustrate the potential of SBSE–RTL-capillary GC–MS.