Assessment of pesticide residues in fresh peach samples produced under integrated crop management in an agricultural region of northern Greece

A multi-residue method using selected ion monitoring mode GC/MS has been developed for the quantitative analysis of residue levels of 23 widely used pesticides in fresh peaches produced under integrated crop management process (ICM). The proposed methodology involved a sample extraction procedure using liquid–liquid partition with acetonitrile followed by a clean-up step based on solid-phase extraction (SPE). Fortification studies were performed at different concentration levels for various types of peaches that differ in properties, such as appearance, flavor and pit. The data showed that the different peach matrices had no significant effect on recoveries. Recoveries were greater than 80% for most of the pesticides with a RSD below 18%. The limits of quantification (LOQs) were in the range 0.002–0.050 mg kg^?1, depending on the compound. To assess method performance with real samples and determine whether pesticide concentrations in peaches exceed their maximum residue levels (MRLs), the proposed method was successfully applied to the analysis of 104 fruit samples collected under integrated pest management (IPM) production during the 2006 cultivation period. Residues detected were lower than those established by legislation for all pesticides, except diazinon, where one positive sample was detected at a level of 0.03 mg kg^?1.     

Effect of household and industrial processing on the levels of pesticide residues and degradation products in melons

Two varieties of melons (Cucumis melo) were treated with two fungicides (carbendazim and maneb) and four insecticides (acetamiprid, cyromazin, imazalil and thiamethoxam) to quantify the effect of household processing on the pesticide residues. To ensure sufficiently high levels of residues in flesh and peel, the most concentrated formulations were applied observing good agricultural practice. The peeling step decreased the concentration of pesticide residues for maneb, imazalil and acetamiprid by more than 90%. Cyromazin, carbendazim and thiamethoxam were reduced by approximately 50%. The reduction of the pesticides could not be fully explained by the systemic character of the pesticides. However, the agricultural practices (time of application), solubility and mode of action (systemic versus contact pesticide) of the pesticides could be used to explain the difference in processing factors for the studied pesticides. Degradation products (melamine and ethylenethiourea) were also investigated in this study, but were not detected.     

Pesticide residues in conventionally grown and organic New Zealand produce

A study was carried out to determine the prevalence and concentrations of pesticide residues in conventionally grown and organic produce (bananas, broccoli, grapes, lettuce, potatoes, tomatoes, wine). Sampling was stratified, with organic produce being over-sampled, when available. All food samples were analysed, as received, by a multi-residue pesticide residue screen. Residues were found in 130 of 307 conventionally grown food samples (42%) and in nine of 41 organic food samples (22%), including six of eleven (55%) organic tomato samples. Only four organic samples (9.8%) contained multiple residues, while 24% of conventionally grown food samples contained multiple residues. Nine conventionally grown food samples (2.6%) contained pesticide residues that exceeded the maximum residue limit (MRL). Where direct comparisons were possible between conventionally grown and organic produce, the mean concentration of residues was usually lower in the organic produce, but was generally higher than would be expected from spray drift or other adventitious sources. While the presence of these residues does not represent a significant risk to human health, their presence is inconsistent with consumer expectations for organic produce.     

Pesticide and veterinary drug residues in honey - validation of methods and a survey of organic and conventional honeys from Slovenia

ABSTRACT

Four analytical methods were developed and validated for the determination of veterinary drug residues and environmental pesticide residues in honey: (a) GC-MS method for the analysis of amitraz and all metabolites containing the 2,4-dimethylaniline moiety; (b) GC-MS method for the analysis of thymol, chlorfenvinphos and coumaphos; (c) GC-MS method for the analysis of 75 active substances; (d) LC-MS/MS method for the analysis of 60 active substances. Between the GC-MS (method c) and the LC-MS/MS method (method d) there was no overlap among active substances, meaning that using both methods 135 active substances originating from the environment in total were included and validated. The first method involved hydrolysis of amitraz and its metabolites containing the 2,4-dimethylaniline moiety to 2,4-dimethylaniline and extraction of 2,4-dimethylaniline to n-hexane. The other three methods had the same extraction procedure with a mixture of solvents: acetone, dichloromethane and petroleum ether. All 4 methods were tested in practice. Sixty samples of honey were analysed: 22 from organic and 38 from conventional production. Overall, residues were mainly higher than reported in literature but did not exceed MRLs. Risk assessment confirmed that the analysed samples are of no cause for concern for consumers.     

UNE-EN ISO/IEC 17025:2005-accredited method for the determination of pesticide residues in fruit and vegetable samples by LC-MS/MS

A rapid, simple and sensitive multi-residue method was developed and validated for the simultaneous quantification and confirmation of 69 pesticides in fruit and vegetables using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted following the quick, easy, cheap, effective, rugged and safe method known as QuEChERS. Mass spectrometric conditions were individually optimised for each analyte in order to achieve maximum sensitivity in multiple reaction monitoring (MRM) mode. Using the developed chromatographic conditions, 69 pesticides can be separated in less than 17 min. Two selected reaction monitoring (SRM) assays were used for each pesticide to obtain simultaneous quantification and identification in one run. With this method in SRM mode, more than 150 pesticides can be analysed and quantified, but their confirmation is not possible in all cases according to the European regulations on pesticide residues. Nine common representative matrices (zucchini, melon, cucumber, watermelon, tomato, garlic, eggplant, lettuce and pepper) were selected to investigate the effect of different matrices on recovery and precision. Mean recoveries ranged from 70% to 120%, with relative standard deviations (RSDs) lower than 20% for all the pesticides. The proposed method was applied to the analysis of more than 2000 vegetable samples from the extensive greenhouse cultivation in the province of Almería, Spain, during one year. The methodology combines the advantages of both QuEChERS and LC-MS/MS producing a very rapid, sensitive, accurate and reliable procedure that can be applied in routine analytical laboratories. The method was validated and accredited according to UNE-EN-ISO/IEC 17025:2005 international standard (accreditation number 278/LE1027).     

Matrix‐Matching as an Improvement Strategy for the Detection of Pesticide Residues

More than 90% of the pesticides residues in apples are located in the peel. We developed a gas chromatography/ion trap tandem mass spectrometry method for investigating all detectable residues in the peel of 3 apple varieties. Sample preparation is based on the use of the Quick Easy Cheap Effective Rugged and Safe method on the whole fruit, the flesh, and the peel. Pesticide residues were quantified with solvent‐matched and matrix‐matched standards, by spiking apple sample extracts. Matrix effects dependent on the type of extract (fruit, flesh, or peel) and the apple variety were detected. The best data processing methods involved normalizing matrix effect rates by matrix‐matched internal/external calibration. Boscalid, captan, chlorpyrifos, fludioxonil, and pyraclostrobin were the most frequently detected pesticides. However, their concentrations in the whole fruit were below European maximum residue levels. Despite negative matrix effects, the residues in peel were detected at concentrations up to 10 times higher than those in whole fruits. Consequently, other pesticide residues present at concentrations below the limit of quantification in the whole fruit were detected in the peel.     

Investigation of pesticide residues in vegetables and fruits grown in various regions of Hatay,Turkey

In this study, 175 pesticide residues in various vegetable and fruit samples grown in different regions of Hatay, Turkey, were investigated. Residue analyses were performed using liquid chromatography–tandem mass spectrometry with the QuEChERS method. In tomato, plum and apricot samples, pesticide residues were below the limits of detection. In other samples, at least one pesticide residue was detected. Twelve pesticides (acetamiprid, carbendazim, chlorpyrifos, fenarimol, fludioxonil, hexythiazox, imidacloprid, metalaxyl, pyridaben, pyriproxyfen, thiabendozole, triadimenol) were found at levels between 0.003 and 0.759?mg?kg^?1. Only in cucumber samples, acetamiprid residues were found at levels greater than the maximum acceptable limit in Turkish Food Codex and European Union maximum residue limits (EU MRLs). In other samples, the detected residue amounts are less than the MRLs declared in the Turkish Food Codex and EU MRLs.     

Pesticide residues in field‐sprayed and processed fruits and vegetables

This study was initiated to determine what residues of six insecticides (organochlorine, organophosphorus and pyrethroids) and four dithiocarbamate fungicides remained on raw agricultural commodities after harvest and to study the effect of the subsequent commercial processing on the residues. Sprayed crops of tomatoes, red peppers, asparagus, spinach, artichokes and peaches harvested after controlled field trials contained residues well below the maximum residue levels, except for lindane in tomatoes and acephate in artichoke. Commercial processing procedures led to large reductions in residue levels in the finished products. Washing removed all residual lindane, chlorpyrifos and cypermethrin from tomatoes. Chlorpyrifos residues were reduced by 67% during wood‐fire roasting of peppers, and subsequent peeling removed all the remains. Peeling and blanching of asparagus reduced chlorpyrifos concentrations to undetectable levels. Processing of artichokes eliminated acephate and chlorpyrifos after blanching. Acephate in peaches survived successive processing steps until the final heat process that destroyed remaining residues. The net results can contribute to assure the consumer of a safe wholesome food supply. Copyright © 2004 Society of Chemical Industry     

Variability in captan residues in apples from a Canadian orchard

Apple trees in an orchard in Quebec, Canada were treated, following label directions, with the fungicide captan (1,2,3,6-tetrahydro-N-(trichloromethylthio)phthalimide) during the 2003 agricultural season. A total of 142 apples from three rows of trees were selected for determination of captan by GC/MS. Individual apples were found to contain captan levels ranging from 16.9 to 6350 ng g^-1. Only two individual apple samples exceeded the Canadian maximum residue limit (5000 ng g^-1) for captan in apples. Six composite samples, comprising half portions of eight individual apples, were analysed from each of the three experimental rows. Composite samples ranged in concentration from 166 to 2620 ng g^-1. The greatest uncertainty associated with the measured concentrations was due to variability among apples rather than the measurement of residue levels.     

Pesticide multiresidue analysis of peanuts using automated gel permeation chromatography clean-up/gas chromatography-mass spectrometry

A method based on automated gel permeation chromatography (GPC) and on-line quantitative concentration was developed for the determination of residues of 38 typically used pesticides in high-oil peanuts. Pesticides were extracted using acetonitrile into an oil fraction containing little of the peanut matrix. After changing the solvent to the mobile phase (1 : 1 cyclohexane : ethyl acetate), clean-up was carried out using GPC, the final collected solution being automatically concentrated to a fixed volume and transferred into vials for gas chromatography (GC) injection. The pesticides were analysed by gas chromatography-mass spectrometry (GC/MS) in the selected ion monitoring (SIM) mode. Average recoveries (spiked levels of 0.02, 0.05, and 0.1 µg g^?1) were between 70 and 117%. The relative standard deviation of the method was 3.5–21% (n = 6). This approach gave comparable results with a previously published method.     

气相色谱-三重串联四极杆质谱法测定粮谷中169种农药的残留量

建立了粮谷中169种农药多残留的气相色谱-三重串联四极杆质谱(GC-MS/MS)的检测方法。样品经改进的QuEChERS净化处理,气相色谱分离,串联四级杆质谱多反应监测方式检测。结果表明,169种农药在粮谷中的检出限为0.3～13.0μg/kg,定量限为1.0～40.0μg/kg,线性范围在0.005 mg/L～2.0 mg/L之间,线性相关系数大于0.99,平均回收率在65.3%～143.6%之间,97%的农药相对标准偏差小于20%,该方法具有前处理简单、净化效果好、灵敏度高的特点,适用于粮谷中多组分农药残留的快速确认和定量检测。     

不同种类固相萃取柱测定韭菜中58种农药残留量的净化效果比较

在比较不同种类的固相萃取柱净化效果上优化了前处理条件,建立了韭菜基质中58种农药残留的气相色谱-质谱法(GC/MS)检测方法。试样经乙腈提取,采用石墨化炭黑/氨基柱(PC/NH₂)净化后,用GC/MS选择离子监测扫描模式(SIM)进行检测,基质匹配溶液外标法定量。结果表明,目标物在65.2~1043.0 ng/mL范围内呈良好的线性相关,相关系数(r)均不小于0.990,方法的检出限(LOD,S/N=3)为0.001~0.007 mg/kg,定量限(LOQ,S/N=10)为0.003~0.024 mg/kg。分别在韭菜基质中做低、中、高3个添加水平的加标回收试验,该方法的平均回收率为62.2%~125.2%,相对标准偏差RSD(n=3)在0.5%~9.5%之间。该方法样品处理简单快速,相比QuEChERS的净化效果要好,灵敏度和选择性高,适用于韭菜复杂基质中多组分农药的筛查确证和定量分析。     

我国主产地柑橘的农药残留现状研究

我国柑橘生产使用农药种类多、剂量大,对产品质量安全有一定影响。文中采用气相色谱和高效液相色谱检测技术,对我国6省(市)柑橘产地抽取的198个鲜果样品进行了26种农药残留的检测与评价。10种农药残留检出,包括禁限用农药,其中1个样品有1种农残超标,超标率为0.47%,各省(市)柑橘鲜果样品的农药残留检出率均在48.9%以上,我国柑橘质量安全存在潜在风险。     

Pesticide residues in grapes from vineyards included in integrated pest management in Slovenia

Although the list of pesticides used in integrated pest management (IPM) in grape growing and their annual application rates are limited, we are still confronted with the problem of pesticide residues in grapes. This paper presents the results of pesticide monitoring of 47 samples of wine grapes (Vitis vinifera L.) from the 2006 vintage from vineyards included in IPM. The grape samples were analysed for the presence of 67 pesticides. Among them 20 were allowed in IPM in 2006. Grapes were sampled at harvest. Two internal analytical methods were used for the determination of pesticides: gas chromatography-mass spectrometry (GC-MS) method for the determination of dithiocarbamates and a multi-residue GC-MS method. One grape sample (2.1%) contained no residues or they were below the limit of detection, 28 samples (59.6%) contained residues lower or equal than maximum residue levels (MRLs), and 18 samples (38.3%) exceeded national MRLs for cyprodinil (the concentration range was 0.03–0.40 mg kg^?1 of cyprodinil) and fludioxonil (concentration was 0.03 mg kg^?1 of fludioxonil). Multiple residues were found in 41 samples (87.2%). The highest number of pesticides detected per sample was seven. No violation of pesticides allowed in IPM was observed. Folpet (97.9%), cyprodinil (51.1%), dithiocarbamates (44.7%), chlorothalonil (23.4%), chlorpyriphos (19.1%) and pyrimethanil (14.9%) were the most frequently found pesticides in grapes. Risk assessment showed that the exceeded concentrations of cyprodinil and fludioxonil did not represent any risk for consumer's health (the national estimate of short-term intake as a percentage of the acceptable daily intake was below 100%).     

Pesticide residues in grapes from vineyards included in integrated pest management in Slovenia

Although the list of pesticides used in integrated pest management (IPM) in grape growing and their annual application rates are limited, we are still confronted with the problem of pesticide residues in grapes. This paper presents the results of pesticide monitoring of 47 samples of wine grapes (Vitis vinifera L.) from the 2006 vintage from vineyards included in IPM. The grape samples were analysed for the presence of 67 pesticides. Among them 20 were allowed in IPM in 2006. Grapes were sampled at harvest. Two internal analytical methods were used for the determination of pesticides: gas chromatography-mass spectrometry (GC-MS) method for the determination of dithiocarbamates and a multi-residue GC-MS method. One grape sample (2.1%) contained no residues or they were below the limit of detection, 28 samples (59.6%) contained residues lower or equal than maximum residue levels (MRLs), and 18 samples (38.3%) exceeded national MRLs for cyprodinil (the concentration range was 0.03-0.40 mg kg^-1 of cyprodinil) and fludioxonil (concentration was 0.03 mg kg^-1 of fludioxonil). Multiple residues were found in 41 samples (87.2%). The highest number of pesticides detected per sample was seven. No violation of pesticides allowed in IPM was observed. Folpet (97.9%), cyprodinil (51.1%), dithiocarbamates (44.7%), chlorothalonil (23.4%), chlorpyriphos (19.1%) and pyrimethanil (14.9%) were the most frequently found pesticides in grapes. Risk assessment showed that the exceeded concentrations of cyprodinil and fludioxonil did not represent any risk for consumer's health (the national estimate of short-term intake as a percentage of the acceptable daily intake was below 100%).     

UPLC-MS／MS法测定大米中9种硫代氨基甲酸酯类农药残留

本文建立了超高效液相色谱-串联质谱（UPLC-MS/MS）检测大米中9种硫玳禽基甲酸酯类农药残留的方法。9种硫代氨基甲酸酯类农药在1．0-100岭／L范围内线性良好,相关系数为0．9966-0．9993,定量限小于0．5μg／L;9种目标物的回收率为76．0％-120．0％,相对标准偏差为2．2％19．6％。该方法准确、灵敏、快速,可满足大米中9种氨基甲酸酯类农药残留量的检测需要,该研究对食品安全及风险预警具有一定参考意义。     

气相色谱-串联质谱法测定鲜猴头菇中16种农药残留

建立气相色谱-串联质谱（GC-MS/MS）法测定猴头菇中16种农药残留的定性、定量分析检测方法。样品经乙腈旋涡振荡提取、净化、浓缩、过滤、定容后,采用气相色谱串联质谱进行定性、定量检测分析。结果表明,16种农药在质量浓度为0.05～1.00 μg/mL范围内的线性关系良好,相关系数（R2）为0.998 6～0.999 9。在猴头菇样品中分别添加质量浓度为0.05 mg/kg、0.20 mg/kg、0.40 mg/kg的混合农药组分,平均回收率为86.08%～93.63%,相对标准偏差（RSD）为3.96%～8.92%,检出限为0.010～0.075 mg/kg。该法操作便捷、灵敏度高、回收率良好、精密度可靠,适用于猴头菇中多种有机农药残留的同时检测。     

氯霉素类抗生素残留分析研究进展

本文综述了近几年来国内外畜禽产品、水产品、食品原料中氯霉素残留分析方法.从专一性强、灵敏度高的ELISA测定方法,到定量的液相色谱法和气相色谱法,以及残留确认的色质联用法.本文分别综述了各种方法的优势与不足,最后展望了氯霉素残留检测的发展趋势.