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.     

Analysis of herbicide residues in cereals, fruits and vegetables

The determination of herbicide residues in cereals, fruits and vegetables by chromatographic methods is reviewed. The principal chemical groups of herbicides, like phenoxyacids, benzonitriles, ureas, triazines, dinitroanilines, chloroacetamides, carbamates, uracils, glyphosate and bipyridylium compounds, are considered. This review briefly provides some basic information on food sample extraction, clean-up, derivatization and determination of herbicide residues.     

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.     

Determination of abamectin residues in fruits and vegetables by high-performance liquid chromatography

A rapid and sensitive HPLC method has been developed and validated for the determination of abamectin residues (avermectin B1a and B1b, as well as the metabolite 8,9-Z-avermectin B1) in apples, pears and tomatoes. Residues are extracted with acetonitrile. The diluted extract is cleaned up on a C18 solid-phase extraction cartridge. Abamectin residues are derivatised with trifluoroacetic acid and 1-methylimidazole and determined by reversed-phase liquid chromatography with fluorescence detection (excitation: 365 nm and emission: 470 nm). High and consistent recoveries, ranging from 88 to 106%, were obtained, at spiking levels of 10, 20 and 50 micrograms/kg, when analysing apples, pears and tomatoes.     

蔬菜、水果中多农药残留的筛查

近年来,食品安全问题引起了人们的高度重视,农药残留污染是制约食品安全的重要因素.在食品农药残留检测方法中,农药残留检测的种类越来越多,农药残留的限量标淮越来越严,人们对食品中农药残留的检测正在不断地探索快速准确的有效方法[1].解卷积报告软件(DRS)是由安捷伦公司研发,其目的主要用于农药和可疑内分泌干扰物的筛查.该软件由安捷伦质谱工作站、自动质谱解卷积和鉴定系统(AMDIS)以及NIST检索三部分组成.AMDIS需要使用包含有保留时间的自动质谱解卷积和鉴定系统.DRS能大大提高复杂基质中痕量化合物的定性能力,并且在SCAN和SIM两种模式下均可采用DRS进行数据处理.保留时间锁定(RTL)和RTL数据库是DRS的一个组成部分,它无需使用标样,只需采用数据库中建立的GC/MS条件,即可实现对农药和一些内分泌干扰物分析鉴定.     

Pesticide residues in fresh fruit and vegetables on the Swedish market, January 1985–December 1989

Conclusion Compared with the previous investigation in 1981–1984, the frequency of samples of fruit and vegetables with excessive amounts of pesticides has decreased from 3.9% to 3.4%.     

气相色谱-质谱法测定蔬菜和水果中193种农药的残留量

在系统优化固相萃取吸附剂填料类型、洗脱溶剂种类及体积的基础上,建立了蔬菜和水果中193种农药残留的气相色谱-质谱(GC-MS)检测方法。样品经乙腈均质提取,C₁₈/PSA固相萃取柱净化,乙腈洗脱,GC-MS选择离子监测(SIM)模式检测,以磷酸三苯酯内标法定量。结果表明,130种农药在10~1000 μg/L、34种农药在20~1000 μg/L、26种农药在50~1000 μg/L、3种农药在100~1000 μg/L范围内线性关系良好,相关系数为0.9967~1.0000,方法检出限(以信噪比为3计)为0.04~8.26 μg/kg,添加回收率为71.6%~117.9%,相对标准偏差为3.0%~11.8%。该方法样品处理简单快速,相比其他多残留分析方法净化效果好,其灵敏度和选择性明显提高,适用于日常检测工作。     

SIM-GC-MS法快速检测蔬菜水果中23种有机磷农药残留

目前,高活性、低残留的有机磷农药仍然是病虫害防治的主要手段。欧盟、美国、日本均已立法制定了食品中有机磷农药含量的严格标准。因此,对农产品特别是新鲜蔬菜、瓜果实施有机磷农药残留检测,已成为社会各界共同关注的焦点。     

MSPD-RRLC-UV/MS法同时检测果蔬中9种三嗪类除草剂残留量

基于基质固相分散萃取(MSPD)-快速高分离液相色谱紫外和质谱检测法, 测定了果蔬中9种三嗪类除草剂的残留量. 以浓度与色谱峰面积之间的线性关系定量, 保留时间结合质谱信息进行定性. 9种待测物在0.02～4.0 mg/kg范围内峰面积与浓度具有良好的线性关系, 相关系数(r2)在0.9996～0.9998之间; 方法的最低检出限(LOD)为0.002 mg/kg; 低、中和高3个浓度点的加标回收率介于75.2%～95.6%之间, 相对标准偏差(RSD)小于11%.     

QuEChERS-液相色谱-串联质谱法同时测定果蔬中16种农药残留

建立了果蔬中吡虫啉、咪鲜胺、苯醚甲环唑、嘧菌酯、噻虫嗪等16种常见农药多残留的液相色谱-串联质谱(LC-MS/MS)分析方法。以乙腈为提取剂,样品经高速匀浆方法提取后,提取液采用液-液萃取静置分层,取上清液进行净化处理。比较了石墨化碳-氨基复合固相萃取与QuEChERS两种不同净化技术的净化效果,最终确定采用QuEChERS方法为净化手段。即提取液经装有150 mg N-丙基乙二胺(PSA)填料、900 mg无水硫酸镁的净化管净化,除去样品中大部分的色素及有机酸等干扰基质,再经LC-MS/MS分析,有效地降低了样品中的复杂基质所带来的背景干扰。加标水平为5、10、20 μg/kg时,16种农药的平均回收率为75%~111%,相对标准偏差小于16%。16种农药的检出限为0.2~5 μg/kg。采用LC-MS/MS定性分析、基质匹配标准曲线法定量分析,线性关系和回收率结果均令人满意。实验证明,建立的QuEChERS净化与LC-MS/MS相结合的检测方法具有快速、准确、灵敏度高等优点,能够准确测定果蔬中16种农药残留。     

Analysis of pesticide residues in fruits, vegetables, and milk by gas chromatography/tandem mass spectrometry.

A method for detection, quantitation, and confirmation of more than 100 pesticides by gas chromatography (GC) with ion trap mass spectrometry (MS/MS) has been developed. The sensitivity of this method for many analytes is equal to or lower than those of selective GC detectors such as flame photometric detectors and electrolytic conductivity detectors. Using MS/MS, very low detection limits and good confirmation (1 precursor ion and 2 or more product ions) are achieved simultaneously. The entire list of pesticides is screened with 2 injections per sample. Samples are introduced onto the column by a temperature-programmed cold injection to maximize response. Each pesticide is run with its own unique set of parameters, which fragment the compound, retaining only the precursor ion. This ion is then refragmented to create a product spectrum. The selectivity of MS/MS gives a very clean spectrum, making compound identification and confirmation clear, even with a relatively dirty food matrix. If care is taken to maintain the injection port and guard column, this method can reliably identify and confirm more than 100 pesticides at the low parts-per-billion range.     

气相色谱-四极杆飞行时间质谱准确鉴定常见水果蔬菜中的农药残留

建立了一种新型农药多残留检测方法。采用气相色谱-四极杆飞行时间质谱（GC-QTOF MS）结合Carbon NH₂柱固相萃取净化可对不同类别的152种农药残留进行准确的鉴定。一级（MS¹）精确质量数据库评价3~5个特征离子,以3个及以上特征离子检出且离子丰度比（Q/q_i）合适作为一级质谱定性依据。对部分特征离子数不足及特征离子检出情况不符合条件的农药进行二级（MS²）确证,应用二级谱图库检索及镜像结果对比分析实现疑似农药确证。本文对梨、甘蓝、番茄3种代表性果蔬在5.0和10.0 μg/kg 2个添加水平的152种农药进行测定,回收率在70%~120%范围的比例分别为甘蓝91.45 %、94.08%,番茄88.20%、88.80%,梨86.84%、92.10%。本方法为常见果蔬中农药残留的准确判断提供了可靠依据,扩大了分析范围。     

Analytical methods for estimation of organophosphorus pesticide residues in fruits and vegetables: A review

Use of pesticides has turned out to be an obligatory input to agriculture and public health. Versatile use of pesticides had resulted in contamination of all basic necessities of life, i.e. air, water and food. Among various pesticides, organophosphorus pesticides (OPPs), derivative of phosphoric acid, are the most extensively used insecticides or acaricides in many crops. Due to low persistency and high killing efficiency of OPPs, many agriculturalists regularly use this group of pesticides for various vegetables and fruits crops. The continuous use of pesticides has caused the deleterious effects to ecosystem. In response to this, a number of methods have been developed by several regulatory agencies and private laboratories and are applied routinely for the quantification and monitoring of multi pesticide residues in vegetables and crops. The present review pertains to various extraction and quantification procedures used world wide to analyze OPPs residues in various vegetables and fruits.     

Determination of carbamate residues in fruits and vegetables by matrix solid-phase dispersion and liquid chromatography-mass spectrometry

Thirteen carbamates were analysed in orange, grape, onion and tomatoes by matrix solid-phase dispersion (MSPD) followed by liquid chromatography-mass spectrometry (LC-MS). Electrospray (ES) and atmospheric pressure chemical ionisation (APCI) were compared and both gave similar results in terms of sensitivity and structural information because at 20 V fragmentor voltages the fragmentation is minimal. The efficiency of different solid-phases (C18, C8, cyano, amine and phenyl) for the MSPD was compared. Mean recoveries using C8 varied from 64 to 106% with relative standard deviations of 5-15% in the concentration range of 0.01-10 mg kg(-1). Matrix constituents did not interfere significantly with the ionisation process of carbamates. The limits of detection were typically in the 0.001-0.01 mg kg(-1) range, which were between 10 and 100 times lower than the maximum residue levels (MRLs) established by the European Union (EU). The method was applied to residue detection in fruit and vegetable samples taken from Valencian markets, in which carbamates were detected at low concentrations.     

液相色谱法检测水果蔬菜中的烟碱类农药残留

建立了果蔬样品中5种烟碱类农药(噻虫嗪、吡虫啉、啶虫脒、噻虫啉、噻虫胺)残留的液相色谱快速检测方法。样品采用乙腈提取,浓缩,水转溶后经ENVI-18固相萃取柱净化,0.02 mol/L NaOH预淋洗除去柱上中等极性干扰物,100%乙腈1 mL洗脱5种烟碱类残留,反相高效液相色谱-二极管阵列检测器检测。在黄瓜空白基质中0.1~1.0 mg/kg的加标浓度范围内,5种农药的回收率为50.8%~108.9%,相对标准偏差(RSD)小于15%;而苹果、梨、香蕉、西红柿和韭菜空白基质在0.1~1.0 mg/kg添加水平下,5种农药的回收率均大于80%,RSD小于11%。所测试的6种果蔬样品中噻虫嗪、噻虫胺、吡虫啉的检出限(LOD)为0.01~0.02 mg/kg,啶虫咪和噻虫啉的LOD为0.03~0.05 mg/kg,方法可满足水果蔬菜中烟碱类农药多残留分析的要求。     

Optimization of headspace solid-phase microextraction for the determination of pesticide residues in vegetables and fruits.

A headspace solid-phase microextraction method has been developed for the determination of 8 pesticides in vegetables and fruits by using gas chromatography with an electron capture detector. Two types of fibers (polyacrylate, 85 microm and polydimethylsiloxane, 100 microm) have been assayed and compared. The main factors: extraction and desorption parameters, ionic strength, and the effects of dilution and organic solvents, were studied and optimized. The optimized procedures resulted in more than 80% recovery for all the investigated vegetable and fruit samples with RSD values below 10%.     

Determination of fungicide residues in fruits and vegetables by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

A liquid chromatography (LC) method for the quantitative determination of five fungicide residues (dichloran, flutriafol, o-phenylphenol, prochloraz and tolclofos methyl) in oranges, lemons, bananas, peppers, chards and onions is described. The residues were extracted by matrix solid-phase dispersion (MSPD) using C8. Quantitative analysis was performed by isocratic LC coupled to quadrupole mass spectrometer using atmospheric pressure chemical ionization in the negative ionization mode. The limit of quantification was 0.01 mg kgmicro for flutriafol, o-phenylphenol and dichloran, and 0.1 mg kg(-1) for prochloraz and tolclofos methyl. The MSPD method is also suitable for LC-UV analysis but higher limits of quantification (between 1 and 5 mg kg(-1)) were obtained. Validation of the method was performed between 0.01 and 25 mg kg(-1). Recoveries for fungicides ranged from 52.5 to 91.1% with relative standard deviations between 6.1 and 11.9%. The method was applied to the determination of residues in samples taken from agricultural cooperatives. The fungicides most often detected were o-phenylphenol and prochloraz.     

Comparison of QuEChERS sample preparation methods for the analysis of pesticide residues in fruits and vegetables

This article describes the comparison of different versions of an easy, rapid and low-cost sample preparation approach for the determination of pesticide residues in fruits and vegetables by concurrent use of gas and liquid chromatography (GC and LC) coupled to mass spectrometry (MS) for detection. The sample preparation approach is known as QuEChERS, which stands for “quick, easy, cheap, effective, rugged and safe”. The three compared versions were based on the original unbuffered method, which was first published in 2003, and two interlaboratory validated versions: AOAC Official Method 2007.01, which uses acetate buffering, and European Committee for Standardization (CEN) Standard Method EN 15662, which calls for citrate buffering. LC–MS/MS and GC–MS analyses using each method were tested from 50 to 1000 ng/g in apple–blueberry sauce, peas and limes spiked with 32 representative pesticides. As expected, the results were excellent (overall average of 98% recoveries with 10% RSD) using all 3 versions, except the unbuffered method gave somewhat lower recoveries for the few pH-dependent pesticides. The different methods worked equally well for all matrices tested with equivalent amounts of matrix co-extractives measured, matrix effects on quantification and chemical noise from matrix in the chromatographic backgrounds. The acetate-buffered version gave higher and more consistent recoveries for pymetrozine than the other versions in all 3 matrices and for thiabendazole in limes. None of the versions consistently worked well for chlorothalonil, folpet or tolylfluanid in peas, but the acetate-buffered method gave better results for screening of those pesticides. Also, due to the recent shortage in acetonitrile (MeCN), ethyl acetate (EtOAc) was evaluated as a substitute solvent in the acetate-buffered QuEChERS version, but it generally led to less clean extracts and lower recoveries of pymetrozine, thiabendazole, acephate, methamidophos, omethoate and dimethoate. In summary, the acetate-buffered version of QuEChERS using MeCN exhibited advantages compared to the other tested methods in the study.