title: Determination of nerve agent metabolites in human urine by isotope-dilution gas chromatography-tandem mass spectrometry after solid phase supported derivatization.
abstract: A simple and sensitive method has been developed and validated for determining ethyl methylphosphonic acid (EMPA), isopropyl methylphosphonic acid (IMPA), isobutyl methylphosphonic acid (iBuMPA), and pinacolyl methylphosphonic acid (PMPA) in human urine using gas chromatography-tandem mass spectrometry (GC-MS/MS) coupled with solid phase derivatization (SPD). These four alkyl methylphosphonic acids (AMPAs) are specific hydrolysis products and biomarkers of exposure to classic organophosphorus (OP) nerve agents VX, sarin, RVX, and soman. The AMPAs in urine samples were directly derivatized with pentafluorobenzyl bromide on a solid support and then extracted by liquid-liquid extraction. The analytes were quantified with isotope-dilution by negative chemical ionization (NCI) GC-MS/MS in a selected reaction monitoring (SRM) mode. This method is highly sensitive, with the limits of detection of 0.02 ng/mL for each compound in a 0.2 mL sample of human urine, and an excellent linearity from 0.1 to 50 ng/mL. It is proven to be very suitable for the qualitative and quantitative analyses of degradation markers of OP nerve agents in biomedical samples.
authors.affiliation: State Key Laboratory of Toxicology and Antitoxic Countermeasures, and Laboratory of Toxicant Analysis, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Haidian District, Beijing, 100850, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Lin
authors.forename: Jia
authors.initials: J
authors.lastname: Chen
authors.forename: Long
authors.initials: L
authors.lastname: Yan
authors.forename: Lei
authors.initials: L
authors.lastname: Guo
authors.forename: Bidong
authors.initials: B
authors.lastname: Wu
authors.forename: Chunzheng
authors.initials: C
authors.lastname: Li
authors.forename: Jianlin
authors.initials: J
authors.lastname: Feng
authors.forename: Qin
authors.initials: Q
authors.lastname: Liu
authors.forename: Jianwei
authors.initials: J
authors.lastname: Xie
mesh_terms: D001711:Biotransformation; D002619:Chemical Warfare Agents / Q000032:analysis* / Q000378:metabolism; D005464:Fluorobenzenes / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D066298:In Vitro Techniques; D007201:Indicator Dilution Techniques; D057230:Limit of Detection; D059625:Liquid-Liquid Extraction; D063065:Organophosphonates / Q000652:urine*; D009943:Organophosphorus Compounds / Q000652:urine*; D009946:Organothiophosphorus Compounds / Q000652:urine*; D012524:Sarin / Q000652:urine*; D012999:Soman / Q000031:analogs & derivatives* / Q000652:urine*; D005466:Fluorocarbons
chemical_list: D002619:Chemical Warfare Agents; D005464:Fluorobenzenes; D063065:Organophosphonates; D009943:Organophosphorus Compounds; D009946:Organothiophosphorus Compounds; D012524:Sarin; D012999:Soman; C025063:pentafluorobenzyl bromide; D005466:Fluorocarbons; C108318:ethyl methylphosphonic acid; C048760:isopropyl methylphosphonic acid; C046573:pinacolyl methylphosphonic acid; C009680:VX-agent