title: Simultaneous Determination and Quantitation of Paraquat, Diquat, Glufosinate and Glyphosate in Postmortem Blood and Urine by LC-MS-MS.
abstract: 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.
authors.affiliation: 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.
authors.forename: Yun-Chen
authors.initials: YC
authors.lastname: Tsao
authors.affiliation: Department of Forensic Toxicology, Institute of Forensic Medicine, Ministry of Justice, No. 123, Min'an St., Zhonghe Dist., New Taipei City 235, Taiwan.
authors.forename: Yung-Chun
authors.initials: YC
authors.lastname: Lai
authors.affiliation: Department of Forensic Toxicology, Institute of Forensic Medicine, Ministry of Justice, No. 123, Min'an St., Zhonghe Dist., New Taipei City 235, Taiwan.
authors.forename: Hsiu-Chuan
authors.initials: HC
authors.lastname: Liu
authors.affiliation: Department of Justice Sciences, University of Alabama at Birmingham, 1720 2nd Ave South Birmingham, AL 35294, USA.
authors.forename: Ray H
authors.initials: RH
authors.lastname: Liu
authors.affiliation: Department of Forensic Toxicology, Institute of Forensic Medicine, Ministry of Justice, No. 123, Min'an St., Zhonghe Dist., New Taipei City 235, Taiwan dllin@mail.moj.gov.tw.
authors.forename: Dong-Liang
authors.initials: DL
authors.lastname: Lin
mesh_terms: D000613:Aminobutyrates / Q000097:blood / Q000378:metabolism / Q000652:urine; D001344:Autopsy; D002853:Chromatography, Liquid; D003334:Coroners and Medical Examiners; D003643:Death; D004178:Diquat / Q000097:blood / Q000378:metabolism / Q000652:urine; D053593:Forensic Toxicology; D005998:Glycine / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism / Q000652:urine; D006540:Herbicides / Q000097:blood / Q000378:metabolism* / Q000652:urine; D010269:Paraquat / Q000097:blood / Q000378:metabolism / Q000652:urine; D053719:Tandem Mass Spectrometry; D000097797:Glyphosate
chemical_list: D000613:Aminobutyrates; D004178:Diquat; D005998:Glycine; D006540:Herbicides; D010269:Paraquat; D000097797:Glyphosate; C003121:phosphinothricin