title: Determination of O-ethyl S-2-diisopropylaminoethyl methylphosphonothioate (VX) by thermospray liquid chromatography-mass spectrometry.
abstract: The determination of the nerve agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothioate (VX) by thermospray liquid chromatography-mass spectrometry was studied. The solvent system acetonitrile-methanol-0.25 M ammonium acetate was used on a reversed-phase C18 column. By selected ion monitoring at the protonated molecular ion of VX (m/z 268), the predominant peak in its thermospray mass spectrum, an amount of 200 pg could be detected. For the determination of VX in water at levels below 1 ng/ml, preconcentration by C18 cartridges was investigated. The applicability of the method was demonstrated by the determination of VX in spiked river waters. A concentration of 0.1 ng/ml could be detected starting from a water sample of 50 ml. A second application concerned the analysis of water extracts of spiked soil samples.
authors.affiliation: Prins Maurits Laboratory TNO, Rijswijk, The Netherlands.
authors.forename: E R
authors.initials: ER
authors.lastname: Wils
authors.forename: A G
authors.initials: AG
authors.lastname: Hulst
mesh_terms: D002800:Cholinesterase Inhibitors / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009946:Organothiophosphorus Compounds / Q000032:analysis*
chemical_list: D002800:Cholinesterase Inhibitors; D009946:Organothiophosphorus Compounds; C009680:VX-agent