title: Enhancing the response of alkyl methylphosphonic acids in negative electrospray ionization liquid chromatography tandem mass spectrometry by post-column addition of organic solvents.
abstract: A method to enhance the signal intensity and signal-to-noise of several alkyl methylphosphonic acids in negative electrospray ionization liquid chromatography tandem mass spectrometry (ESI LC-MS/MS) is presented. This class of compound represents the initial metabolites and environmental degradants of the nerve agents: VX, rVX (Russian VX), GB (Sarin), GF (Cyclosarin), and GD (Soman). Compared with the post-column addition of the mobile phase, the post-column addition of aprotic solvents and longer chain alcohols enhance the signal intensity and signal-to-noise ratio (S/N) of the chromatographic peaks by factors of up to 60 and 19, respectively. The post-column addition of water, methanol, and ethanol resulted in little or no relative signal enhancement. It is proposed that the post-column addition of these solvents do not result in the same enhancements due to stabilization of analyte solvation through hydrogen bonding.
authors: US Centers for Disease Control and Prevention, National Center for Environmental Health, Division of Laboratory Sciences, Emergency Response and Air Toxicants, Atlanta, Georgia 30341, USA. dbmawhinney@hotmail.com
authors: Douglas B
authors: DB
authors: Mawhinney
authors: Rayman D
authors: RD
authors: Stanelle
authors: Elizabeth I
authors: EI
authors: Hamelin
authors: Robert J
authors: RJ
authors: Kobelski
mesh_terms: D000478:Alkylation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D009930:Organic Chemicals / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012997:Solvents / Q000737:chemistry*; D013048:Specimen Handling / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D009930:Organic Chemicals; D009943:Organophosphorus Compounds; D012997:Solvents; C032627:methylphosphonic acid
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