白菜中农药残留量测定能力验证探讨

为评价参与能力验证实验室的农药残留检测能力，制备农药残留量测定能力验证用白菜样品，根据中国合格评定国家认可委员会(CNAS)相关文件要求，进行样品均匀性和稳定性检验，以稳健统计的中位值作为指定值，采用Z比分数法对参加检测机构的检测结果进行统计评价。结果显示，能力验证测试结果的合格率为94.05%。部分参加检测机构在检测方法应用、检测数据溯源、检测结果校准和检测质量控制等方面存在问题。研究表明，通过分析参加检测机构的原始数据及报告记录，可以发现农药残留检测过程中存在的共性技术问题，并提出相关技术建议，有助于提升实验室的检测技术水平。     

近年国内关于甘蔗中农药残留检测技术研究进展

本文详细介绍了国内近几年来甘蔗中农药残留检测技术的进展,包括样品的前处理技术和农药残留定性定量检测方法,并列举一些应用实例。     

液相色谱-四极杆飞行时间质谱快速筛查洋葱中173种农药残留

应用液相色谱-四级杆飞行时间质谱(LC-QTOF/MS)建立了洋葱中173种农药的快速筛查方法。洋葱样品经含体积分数1%乙酸的乙腈溶液振荡提取,盐析离心,Carbon/NH₂净化,在电喷雾全离子二级质谱扫描 (All Ions MS/MS) 正离子模式下采用LC-QTOF/MS进行检测。选择定性筛查时较为重要的离子个数选择模式,色谱共流出曲线相似度匹配得分 (co-elution score) 以及峰高阈值等参数进行了定性筛查方法的优化,最终确定了对采集结果进行分析的最佳筛查参数。同时,应用该方法对洋葱基质中173种农药的定性和定量方法学参数进行了考察。结果表明:167种农药的筛查限和定量限分别在0.001~0.005 mg/kg和0.001~0.01 mg/kg之间,其余6种的筛查限和定量限分别在0.01~0.025 mg/kg和 0.02~0.05 mg/kg之间。所有化合物在测试浓度范围内线性关系良好。添加回收试验 (n=5) 结果显示,在1倍定量限(LOQ)、2倍LOQ和10倍LOQ 3个添加水平下,173种农药中分别有153、168和165种农药的平均回收率在70%~120%之间,相对标准偏差均在20%以内。将本研究建立的筛查方法应用于2020年欧盟组织的水果蔬菜中农药残留检测能力验证 (EUPT-FV22),准确筛查出了组织方在洋葱样品中添加的农药,而且定量结果满意,表明本研究所建立的LC-QTOF/MS筛查方法准确、可靠,适用于洋葱中农药多残留快速筛查和准确定量。     

农药产品中未知成分的气—质联用分析技术研究

本文通过对接受到的农药样品进行未知成分定性鉴定，介绍了GC－MS技术在农药未知成分分析技术的研究和应用，并举出示例。     

浅谈农药残留分析检测技术的应用现状

文章简单综述了农药残留分析检测的基本过程,介绍了农药残留分析和检测的主要方法以及样品前处理和检测的新技术、新方法,同时对农药残留分析检测技术的前景进行了展望。     

QuEChERS方法在农药多残留检测中的应用研究进展

QuEChERS方法作为一种农药多残留前处理方法,由于具有快速、简单、廉价、有效、可靠、安全的特点而成为了研究的热点。随着气相色谱(GC)、液相色谱(LC)及气相色谱-质谱(GC-MS)和液相色谱-质谱(LC-MS)联用仪器的不断研发改进,其高效的分离能力和定性鉴定能力结合QuEChERS前处理方法,可在短时间内实现对几十种甚至上百种复杂化合物的分离、定性及定量。重点综述了近年来QuEChERS方法在农药多残留检测前处理方面的应用,详细评述了在样品处理、提取、净化及提取液浓缩等方面对QuEChERS方法进行优化改进的研究进展。     

农业部农药检定所开展高毒农药替代产品检测能力验证工作

为进一步加强实验室管理,提高农药质量检测技术水平,确保农药产品质量检测结果的准确可靠,为农药质量监督管理提供技术支撑,根据＂高毒农药替代试验示范＂项目的安排,农业部农药检所决定开展三唑磷原药等4个样品农药质量检测能力验证试验。农药检（分析）[2009]66号文的具体要求如下：     

气相色谱-串联质谱法检测川产丹参中70种农药残留

以中药材丹参为研究对象，通过对样品前处理及色谱分析条件进行优化，建立了丹参中70种禁用及常用农药残留同时检测的气相色谱-串联质谱 (GC-MS/MS) 分析方法，并采用该方法对产自四川不同地市的44批丹参样品进行了农药残留检测筛查。样品加水经乙腈提取，以QuEChERS提取包 (含无水硫酸镁与无水乙酸钠等) 进行盐析，提取液经浓缩后，加入内标磷酸三苯酯，在多反应监测 (MRM) 模式下采用GC-MS/MS检测。结果表明:在1~100 μg/L范围内，70种农药的质量浓度与其峰面积间呈良好的线性关系，相关系数 (r) 均大于0.9985；在3个添加水平 (5 × LOD、10 × LOD和20 × LOD) 下，添加回收率在70%~120%内的农药数量占总数的87.1%，相对标准偏差均小于15%。70种农药的定量限在0.01~0.03 mg/kg之间。对收集到的44批川产丹参样品进行检测发现，其中有22批样品分别检出1~5种农药，包括国家禁用农药三氯杀螨醇。该方法简便、灵敏、准确，可用于川产丹参中多种农药残留的快速筛查与检测，检测结果可为丹参的种植生产和流通监管提供参考。     

QuEChERS结合GC-MS/MS法测定24批次桔梗中34种农药残留

建立基于QuEChERS法结合气相色谱-串联质谱法(GC-MS/MS)对桔梗中34种农药残留量的快速检测方法，并应用于24批桔梗样品筛查。采用QuEChERS法对样品进行前处理，在气相色谱-串联质谱多反应监测(MRM)模式下进行测定，考察其线性关系、定量限、回收率和精密度。以所建立的方法对24批桔梗样品中34种农药残留进行测定分析。34种农药在一定质量浓度范围内线性关系良好，相关系数r均>0.998,其LOQ在0.000 3～0.600 0 mg/kg之间；回收率均在60%～130%范围内，RSD均<15%。有18批次桔梗样品检出农药残留，检出率为75%;检出农药对硫磷、甲基异柳磷、治螟磷、三氯杀螨醇、氟虫腈，其含量均在0.001～0.015 mg/kg之间，低于药典规定的0.02 mg/kg的限度，所检样品合格率为100%;其余农药未检出。所建立的QuEChERS法结合气相色谱-串联质谱法可用于桔梗中34种农药残留物的定性定量分析，可为桔梗的质量管控提供技术支撑。     

中毒检样中氧乐果和克百威的气质联用分析

本文采用液—液萃取方法及GC／MS检测技术，对药剂及其中毒后的组织样品进行了检测，从中均检出氧乐果和克百威的农药成分，建立了该类农药组分的生物组织提取净化方法，并优化了其质谱的分析参数条件。     

Internationally harmonized certified reference materials and proficiency testings for pesticide residue analysis

Matrix certified reference materials (CRMs) and proficiency testings (PTs) are effective for evaluation of the quality of analytical results. The National Metrology Institute of Japan has developed five kinds of CRMs and has provided eight PTs so far for the quantification of pesticide residues in foods. Target pesticides were sprayed on growing crops, and the harvests were used for the preparation of CRMs and PT samples. In most cases, multiple analytical methods based on isotope dilution mass spectrometry were used to ensure the reliability of certified values (for CRMs) and reference values (for PT samples). These activities were carried out with corresponding to the international standards such as ISO 17034 and ISO/IEC 17043. An overview of the development of CRMs and the implementation of PTs is described, with some examples.     

Researches on the evaluation of pesticide safety in humans using a pharmacokinetic approach

Similar to the pharmaceutical compounds, pesticides require human safety assessment for their registration and distribution; however, it is absolutely impossible to assess human safety by dosing humans with pesticides. Thus, how to appropriately evaluate the safety of pesticides in humans remains a great subject of debate. In this article, we present some examples of pesticide toxicity studies that identify species differences in toxicity and evaluate human safety by applying combinations of novel in vivo, in vitro, and in silico techniques to separately assess the key toxicodynamic (i.e., sensitivity) and/or toxicokinetic (i.e., exposure) factors. Because it is scientifically sound, the safety assessment strategy illustrated for three compounds in this article is expected to play an important role in the human safety assessment of agricultural compounds.     

Biota uptake of pesticides by selected plant species; the case study of Kilombero sugarcane plantations in Morogoro Region, Tanzania

This paper reports on biota uptake of pesticides by selected plant species from soil in which they are grown. The study was conducted at Kilombero sugarcane plantations and environs, Morogoro Region, Tanzania. Three species of the plant materials were collected namely sugarcane (Saccharum officinarum), guinea grass (Panicum maximum) and mango leaves (Mangifera indica). The sugarcane and guinea grass were used to reveal the plant uptake in the plantations whereas mango leaves were used to represent the environs. GPC cleaned sample extracts were analysed by GC-ECD and GC-NPD and the results confirmed using GC-MS. A total of 16 different pesticide residues were detected in soil samples and only 11 pesticide residues were detected in flora samples. o,p′-DDT had the highest concentration of all detected pesticides in soil samples with a mean concentration of 21.04 μg/kg d.w. whereas the highest concentrations of 17.16 μg/kg d.w. was recorded for p,p′-DDD in flora samples. The other DDT metabolites detected in soil samples were p,p′-DDT, p,p′-DDE, o,p′-DDE, p,p′-DDD and o,p′-DDD with concentration ranging from 2.00 to 18.30 μg/kg d.w. whereas the other pesticides detected in flora samples were p,p′-DDT α-endosulfan and γ-HCH with a mean concentration range of 3.21 to 13.54 μg/kg d.w. The paired sample t-test showed no significant difference between the concentrations of pesticides in flora and those found in soil.     

Pesticides in surface water runoff in south-eastern New York State, USA: seasonal and stormflow effects on concentrations

Samples from two streams (Kisco River and the Middle Branch of the Croton River) in the Croton Reservoir system in south-eastern New York State, USA were sampled from May 2000 through to February 2001 in order to document the effect of land use, streamflow and seasonal patterns of application on pesticide concentrations in runoff from developed watersheds. Many of the pesticides detected most commonly in this study are generally used in developed areas, and particularly on turfgrass. Pesticide concentrations were generally higher, and the numbers of compounds were generally larger, in samples from the Kisco River than in samples from the Middle Branch, probably because the Kisco River drainage has a greater population density and is more extensively developed. Four pesticides (2,4-D, 2,4-D-methyl, dicamba and metalaxyl) were detected in at least one sample from the Kisco River at a concentration >1 microg litre(-1), and no pesticides were detected at concentrations >0.4 microg litre(-1) in Middle Branch samples. No human-health-based water-quality standards were exceeded by samples from either site in this study, but samples from the Kisco River contained four insecticides (carbaryl, chlorpyrifos, diazinon and malathion) and one herbicide (2,4-D) in concentrations that exceeded water quality criteria for the protection of aquatic life. The highest concentrations of most compounds occurred during stormflows in both streams in June, September and December, 2000. The lowest concentrations of most compounds at both sites occurred during baseflows from October 2000 through February 2001, even though the concentrations of many compounds increased substantially at the Kisco River site during stormflows in November and December. Detailed data on the variability of pesticide concentrations during stormflows indicate that there may be two sources of pesticides in the Kisco River watershed: (1) elevated concentrations of pesticides during peak flows that occur early in stormflows likely reflect runoff from paved areas, and (2) elevated concentrations during peak flows that occur later in stormflows from areas with lesser amounts of pavement. Data from the Kisco River indicate that the relation between storm discharge and pesticide concentrations varies among compounds, in part because of variation in seasonal application patterns. These variations in the timing of application result in not all stormflows producing increased concentrations of pesticides. Overall, these results indicate the importance of stormflow sampling throughout the year in assessing pesticide fate and transport in urbanized, developed areas.     

气相色谱-串联质谱法测定植物样品中17种有机氯农药和8种多氯联苯

建立了植物样品中17种有机氯农药和8种多氯联苯单体的气相色谱-串联质谱(GC-MS/MS)分析方法。样品以 V(丙酮):V(乙酸乙酯)=1:1为溶剂进行提取,采用石墨化炭黑及氨基联合SPE小柱净化,GC-MS/MS测定。25种化合物的平均添加回收率在66.6%~113.1%之间,相对标准偏差(RSD)在4.1%~14.1%之间,方法检出限(MDL)在0.03~0.29 ng/g之间。该方法灵敏度高,满足环境调查的需求。对污染区采集的植物样品进行检测,发现被变压器油污染地区的植物体内含有较高质量分数的PCB28和PCB52,最高达108 ng/g,说明多氯联苯能够通过迁移等途径从土壤传递到植物中。     

Synthesis of novel derivatives of camptothecin as potential insecticides

In an attempt to find the biorational pesticides, a series of novel camptothecin derivatives were synthesized via a simple modification of the carbodiimide method using the combination of scandium triflate (Sc(OTf)₃) and 4-dimethylaminopyridine (DMAP), and their structures were identified by IR, ESR, HRMS and ¹H NMR. Their antifeedant effect and insecticidal activity against third-instar larva of Mythimna separate were examined. The results of preliminary bioassays showed that these compounds exhibited less potent antifeedant activity than camptothecin. Also, all of these derivatives of camptothecin showed delayed insecticidal activity, which differs from traditional neurotoxic insecticides. The results suggested that 20-hydroxyl group in the camptothecin derivatives is essential to keep the insecticidal activity and nature of the substitutes has a major impact on insecticidal activity of these compounds.     

The effectiveness of various acaricides against resistant and susceptible carmine spider mites

Two colonies of the carmine spider mite,Tetranychus cinnabarinus (Boisd.), were raised on beans in the laboratory. One originated from roses in a greenhouse which had received acaricidal treatments, and the other fromViola odorata L. in a garden where no pesticides had been used. Laboratory evaluation indicated that the greenhouse strain was highly resistant to dicofol (Kelthane) and bromopro-pylate (Neoron), moderately resistant to propargite (Omite), and slightly resistant to cyhexatin (Plictran); in the garden strain, there was no resistance to any of these acaricides. On a strain of carmine spider mites which was identified and defined as resistant, several acaricides were evaluated in the laboratory for their contact toxicity to the mite by the slide dip method, and for their contact plus stomach toxicity by exposing the mites to sprayed leaves. Some of these acaricides were later tested in the field on two undetermined populations. Cyhexatin, triazophos (Hostathion), fentrifanil (PP-199) and R-28627 killed more than 90% of the mites by both methods and were effective in the field. NC-13292 was an ovicide only. Proclonol (R-8284) had a good effect in the slide dip method but was not so effective in the leaf exposure test. The compounds tested were phytotoxic to rose foliage only, but triazophos burned all the crops tested.     

Comparative effects of organophosphorus insecticides on the activities of acetylcholinesterase,diacylglycerol kinase,and phosphatidylinositol phosphodiesterase in rat brain microsomes

The activities of acetylcholinesterase, diacylglycerol kinase, and phosphatidylinositol phosphodiesterase in rat brain microsomes were measured in the presence and absence of the organophosphorus insecticides, parathion and diazinon, and their respective oxon analogs, paraoxon and diazoxon. Marked inhibition of acetylcholinesterase (by 45–99%) was observed in the presence of paraoxon (10^?2–10^?6M) and diazoxon (10^?2–10^?4M). Reduction of acetylcholinesterase activity (by 22–33%) was achieved with the parent insecticides at high concentrations only (10^?2M). In most cases, diacylglycerol kinase was insensitive to the pesticides. Marked stimulation of phosphatidylinositol phosphodiesterase (by 10–57%) was observed in the presence of all pesticides (10^?2–10^?3M). The phosphodiesterase exhibited slightly greater sensitivity to the parent compounds compared to the oxon derivatives. Stimulation of the phosphodiesterase by the insecticides was not correlated with acetylcholinesterase inhibition. Accordingly, the increase in phosphodiesterase activity was judged not to be acetylcholine mediated, but rather represented a direct effect of the pesticides on the enzyme or its microenvironment. Based on the present in vitro observations, it is proposed that certain organophosphorus pesticides may interfere with the normal process of synaptic transmission through both the inhibition of acetylcholinesterase and the stimulation of phosphatidylinositol phosphodiesterase. In view of the high concentrations of pesticides required to elicit the latter effect, interpretation of its physiological significance must await results from further studies performed in vivo.     

Influence of Atrazine and Roundup pesticides on biochemical and molecular aspects of Biomphalaria alexandrina snails

The excessive use of pesticides in agriculture has sparkled the interest of scientists in investigating the harmful effects of these compounds. The present study evaluates the pesticides Atrazine and Roundup (glyphosate) on biochemical and molecular aspects of Biomphalaria alexandrina snails. The results showed that LC₁₀ of these two pesticides caused considerable reduction in survival rates and egg production of treated snails. Additionally, Atrazine proved to be more toxic to B. alexandrina snails than Roundup. In treated snails, glucose concentration (GL) in the hemolymph as well as lactate (LT) and free amino acid (FAA) in soft tissues of treated snails increased while glycogen (GN), pyruvate (PV), total protein (TP), nucleic acids (DNA and RNA) levels in snail’s tissues decreased. The activities of glycogen phosphorylase (GP), superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR), succinic dehydrogenase (SDH), acetylcholinesterase (AChE), lactic dehydrogenase (LDH) and phosphatases (ACP and ALP) enzymes in homogenate of snail’s tissues were reduced in response to the treatment with the two pesticides while lipid peroxide (LP) and transaminases (GOT and GPT) activity increased (P < 0.001). The changes in the number, position and intensity of DNA bands induced by pesticides may be attributed to the fact that pesticide can induce genotoxicity through DNA damage. It was concluded that the pollution of the aquatic environment by Atrazine and Roundup pesticides, would adversely affect the metabolism of the B. alexandrina snails, and have adverse effects on its reproduction.     

固相萃取-气相色谱-三重四极杆串联质谱法测定茶叶中45种有机磷农药残留

采用气相色谱-三重四极杆串联质谱(GC-MS/MS)技术建立了茶叶中45种有机磷农药残留的检测方法。茶叶样品加水浸泡后采用乙腈提取，经TPT固相萃取柱净化，用V (乙腈) : V (甲苯) ＝ 3 : 1混合溶液洗脱，采用GC-MS/MS检测，基质匹配标准溶液外标法定量；分析了加水对茶叶中有机磷类农药提取效率的影响。结果表明:45种有机磷类农药在各自质量浓度范围内线性关系良好，相关系数均大于0.993。方法检出限为0.001~0.01 mg/kg，定量限为0.002~0.02 mg/kg。在0.05、0.5和5 mg/kg 3个添加水平下，45种农药平均回收率在71%~102%之间，相对标准偏差均小于9.4%。