Tsao Yun-Chen, Lai Yung-Chun, Liu Hsiu-Chuan, Liu Ray H, Lin Dong-Liang
Department of Forensic Toxicology, Institute of Forensic Medicine, Ministry of Justice, No. 123, Min'an St., Zhonghe Dist., New Taipei City 235, Taiwan School of Pharmacy, College of Medicine, National Taiwan University, No. 33, Linsen S. Rd., Zhongzheng Dist., Taipei City 100, Taiwan.
Department of Forensic Toxicology, Institute of Forensic Medicine, Ministry of Justice, No. 123, Min'an St., Zhonghe Dist., New Taipei City 235, Taiwan.
J Anal Toxicol. 2016 Jul;40(6):427-36. doi: 10.1093/jat/bkw042. Epub 2016 Jun 23.
A simple method, incorporating protein-precipitation/organic backwashing and liquid chromatography-tandem mass spectrometry (LC-MS-MS), has been successfully developed for the simultaneous analysis of four highly water-soluble and less volatile herbicides (paraquat, diquat, glufosinate and glyphosate) in ante- and postmortem blood, urine and gastric content samples. Respective isotopically labeled analogs of these analytes were adopted as internal standards. Acetonitrile and dichloromethane were used for protein precipitation and organic solvent backwashing, respectively, followed by injecting the upper aqueous phase into the LC-MS-MS system. Chromatographic separation was achieved using an Agilent Zorbax SB-Aq analytical column, with gradient elution of 15 mM heptafluorobutyric acid and acetonitrile. Mass spectrometric analysis was performed under electrospray ionization in positive-ion multiple reaction monitoring mode. The precursor ions and the two transition ions (m/z) adopted for each of these four analytes were paraquat (185; 169 and 115), diquat (183; 157 and 78), glufosinate (182; 136 and 119) and glyphosate (170; 88 and 60), respectively. Analyte-free blood and urine samples, fortified with the analytes of interest, were used for method development/validation and yielded acceptable recoveries of the analytes; interday and intraday precision and accuracy data; calibration linearity and limits of detection and quantitation. This method was successfully incorporated into an overall analytical scheme, designed for the analysis of a broad range of compounds present in postmortem samples, helpful to medical examiners' efforts to determine victims' causes of death.
一种结合蛋白质沉淀/有机溶剂反洗和液相色谱-串联质谱法（LC-MS-MS）的简单方法已成功开发出来，用于同时分析生前和死后血液、尿液及胃内容物样本中的四种高水溶性、低挥发性除草剂（百草枯、敌草快、草铵膦和草甘膦）。这些分析物各自的同位素标记类似物被用作内标。分别使用乙腈和二氯甲烷进行蛋白质沉淀和有机溶剂反洗，然后将上层水相注入LC-MS-MS系统。使用安捷伦Zorbax SB-Aq分析柱进行色谱分离，采用15 mM七氟丁酸和乙腈进行梯度洗脱。在电喷雾电离正离子多反应监测模式下进行质谱分析。这四种分析物各自采用的母离子和两个跃迁离子（m/z）分别为百草枯（185；169和115）、敌草快（183；157和78）、草铵膦（182；136和119）和草甘膦（170；88和60）。用添加了目标分析物的不含分析物的血液和尿液样本进行方法开发/验证，得到了可接受的分析物回收率、日间和日内精密度及准确度数据、校准线性以及检测限和定量限。该方法已成功纳入一个整体分析方案，该方案旨在分析死后样本中存在的多种化合物，有助于法医确定受害者的死因。
