【作者】 吕晓玲；

【导师】 王静；

【作者基本信息】 中国农业科学院 ， 农产品质量与食物安全， 2010， 硕士

【摘要】 随着科学技术的发展,化学农药的品种和数量不断增加,农药的超量、滥用等不规范使用所带来的环境污染和残留超标问题及其各类中毒事件已经引起了人们的广泛关注。加强农药残留检测及农药使用的全程管理,开发简便、快速的多残留确证检测方法是控制农药残留的主要技术保障。样品前处理技术是检测方法的核心部分,是衡量检测方法先进性和实用性的重要指标。现在我国很多科研院所和检测机构的仪器设备水平和国外相比差异不大,差距是在样品的提取、净化等前处理上。2003年,美国农业部的Anastassiades和Lehotay等在乙腈提取和分散固相萃取的基础上提出了一种新的样品前处理技术,由于该方法与传统样品前处理相比具有快速(quick)、简单(easy)、便宜(cheap)、有效(effective)、可靠(rugged)和安全(safe)的优点,因而被称为QuEChERS方法。自QuEChERS方法问世以来,国外分析学家已经进行了深入的研究和方法验证,并对该方法进行了改进,目前已经成为美国分析化学家组织(AOAC)和欧洲标准化委员会的标准方法。研究QuEChERS方法的关键技术、将其创新发展并应用于我国的农产品农药残留检测中,具有重要的现实意义。本论文主要探讨QuEChERS方法的影响因素,针对我国最广泛使用的农药种类和全国农产品质量例行监测的农药,建立蔬菜、水果中农药多残留检测的QuEChERS-气相色谱串联质谱方法和QuEChERS-液相色谱串联质谱方法,主要研究内容及结果如下:(1)不同因素对样品提取净化效果的影响。通过研究比较了提取溶剂、盐析除水剂的用量以及分散固相吸附剂种类对样品净化效果的影响,确定了合适的取样量、最佳提取溶剂、除水剂比例和吸附剂用量。结果显示:对于新鲜果蔬样品,取样量与提取溶剂的比例为1:1;取样量与除水剂无水硫酸镁及醋酸钠的比例为10:4:1;吸附剂PSA和C18用量分别为每毫升提取液30mg,GCB的用量为5mg。在净化的过程中按照提取液、甲苯为3:1的比例,加入少量甲苯,可以将吸附在GCB上的目标分析物洗脱下来,提高回收率。(2)蔬菜中40种农药多残留QuEChERS-GC-MS/MS检测方法建立。通过方法的线性范围,精密度和准确度实验,得到以下结论:40种农药目标物在0.02μg/mL~0.5μg/mL的范围内线性关系良好,相关系数r2在0.9901~0.9998之间。在0.05 mg/ kg、0.1 mg/ kg、0.2mg/ kg三个添加水平上,平均回收率在85%~120%之间,相对标准偏差在3.1%~18.3%之间,方法的准确度和精密度均符合残留分析的要求。40种农药的检出限在0.002μg/kg~2.12μg/kg之间,定量限在0.007μg/kg~7.092μg/kg之间,低于我国现有的GC和GC-MS检测方法和标准。(3)蔬菜中29种农药多残留的QuEChERS-LC-MS/MS检测方法建立。研究了液相色谱质谱优化选择,并对方法的精密度和准确度进行研究。结果显示:29种农药在1μg/kg、5μg/kg、10μg/kg的3个添加水平上,平均回收率为70%~119%,RSD小于15.5%,检出限在0.005μg/kg~0.352μg/kg之间,定量限在0.015μg/kg~1.176μg/kg之间。(4)将QuEChERS方法应用于多种蔬菜、水果样品基质的农药多残留检测中,扩大了该方法的应用范围,提高了方法的适用性。更多还原

【Abstract】 As the development of science and technology, the kinds and number of chemical pesticides are increasing day by day. With the increasing and using excessively in agricultural application, concerns have been raised by the public regarding its residue problems and the hazard of poisoning. Development of quick, easy and effective multi-pesticide residues determination method is needed hardly, in order to reinforce the management of pesticide abuse. Sample pretreatment is the critical section in residue determination,it’s the key indicator to measure the advancement and practicability of a new determination method. Nowadays, the technological distance between our country and developed countries is not the instruments but the sample pretreatment such as extraction and clean steps. In 2003, Anastassiades and Lehotay, et al. from the eastern regional research center of United States agricultural department developed a fast and easy multi-residue method employing acetonitrile extraction /partition- ing and“Dispersive solid-phase extraction”for the determination of pesticide residues in produce. The method, compared to other methods has the advantage of quick, easy, cheap, effective, rugged, and safe known as QuEChERS method. Later on, this QuEChERS method was collaboratively studied among 13 labs in 7 countries, and became AOAC Official Method 2007.01 in 2007. Accordingly, study on the critical steps in QuEChERS method and improve it, made it fit for our needs in multi-pesticides residue have important means. The main object in our study is to discuss the critical factor impact the results, choose the most popular used pesticides in our county and the pesticides on the routine monitoring list of ago-products quality as our research targets and develop an adaptive method based on the QuEChERS method for the determination of multi-pesticides residue in vegetables and fruits, details are as follows:(1) Comparing was conducted between extract solvents, amount of salt and dispersive sorbent used in pretreatment and its effect on cleanup. Results as follows: the ratio between fresh sample amount and extract solvents is 1:1, the sample amount: anhydrous magnesium sulfate: sodium acetate is 10:4:1. Adding of toluene at ration of 1:3 to extraction liqulid can effectively improve the planner pesticides recovery decreases caused by the GCB absorb.(2) Develop a GC-MS/MS method based on the QuEChERS procedure to determinate 40 kinds of pesticide residues in vegetables; the linearity, precision and accuracy were investigated. The mean recoveries of all pesticides were in range from 85% to 120%, relative standard deviation were from 3.1% to 18.3% at the 0.05 mg/kg,0.1 mg/kg and 0.2mg/kg Spike level,the precision and accuracy of this method meet the requirement of residue analysis. The limit of determination of 40 kinds of pesticides is between 0.002μg/kg~2.12μg/kg, limit of quantity is between 0.007μg/kg~7.092μg/kg, which is much lower than the most reported GC or GC-MS determinate methods.(3) Develop a LC-MS/MS method based on the QuEChERS procedure to determinate 29 kinds of pesticide residues in vegetables. The liquid chromatography conditions and mass spectrometry conditions were optimized; linearity, precision and accuracy of the method were investigated. The method is reliable and stable that the recoveries of almost all pesticides were in the range from 70% to 119% at the 1μg/kg, 5μg/kg and 10μg/kg spiked level, and the RSD were all below 15.5%. The limit of determination of 29 kinds of pesticides were in the range from 0.005μg/kg to 0.352μg/kg, limit of quantity were in the range from 0.015μg/kg to 1.176μg/kg.(4) The QuEChERS method was applied to more matrixes such as tomato, spinach, cabbage, pear and apple, the applicability and usage scope was discussed.更多还原