US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Ln., Wyndmoor, PA 19038, USA.
J Chromatogr A. 2010 Apr 16;1217(16):2548-60. doi: 10.1016/j.chroma.2010.01.044. Epub 2010 Jan 22.
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 1000ng/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.
本文描述了一种简单、快速、低成本的样品制备方法的不同版本，用于通过气相色谱（GC）和液相色谱（LC）与质谱（MS）联用同时测定水果和蔬菜中的农药残留。该样品制备方法称为 QuEChERS，是“快速、简单、廉价、有效、坚固和安全”的缩写。比较的三个版本基于原始的无缓冲方法，该方法于 2003 年首次发表，以及两个经过实验室间验证的版本：AOAC 官方方法 2007.01，使用乙酸盐缓冲液，以及欧洲标准化委员会（CEN）标准方法 EN 15662，要求使用柠檬酸盐缓冲液。使用每种方法在苹果蓝莓酱、豌豆和酸橙中对 32 种代表性农药进行了 50-1000ng/g 的 LC-MS/MS 和 GC-MS 分析。不出所料，所有 3 个版本的结果都非常出色（总体平均回收率为 98%，相对标准偏差为 10%），除了无缓冲方法对少数 pH 依赖性农药的回收率略低。不同方法对所有测试基质的效果相同，所测量的基质共提取物含量相当，定量时的基质效应以及色谱背景中的基质化学噪声。对于所有 3 种基质中的吡虫啉以及酸橙中的噻菌灵，乙酸盐缓冲版本的回收率更高且更一致。在豌豆中，没有一个版本对氯丹、福美双或托力氟胺的效果始终良好，但乙酸盐缓冲方法在这些农药的筛选方面效果更好。此外，由于乙腈（MeCN）最近短缺，评估了乙酸盐缓冲 QuEChERS 版本中乙酸乙酯（EtOAc）作为替代溶剂，但它通常会导致提取液不够干净，并且吡虫啉、噻菌灵、乙酰甲胺磷、甲胺磷、氧乐果和乐果的回收率降低。总之，与研究中测试的其他方法相比，使用 MeCN 的乙酸盐缓冲 QuEChERS 版本具有优势。
