Reactive desorption electrospray ionization for selective detection of the hydrolysis products of phosphonate esters

✍ Scribed by Yishu Song; R. Graham Cooks

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 192 KB
• Volume: 42
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/jms.1244

✦ Synopsis

Abstract

Reactive desorption electrospray ionization (reactive DESI) is demonstrated to be a rapid and sensitive method for the direct detection of alkyl methylphosphonic acids, the hydrolysis products and metabolites of the chemical warfare (CW) agents VX (S‐2‐diisopropylaminoethyl‐O‐ethyl methylphosphonothiolate) and GB (sarin, isopropylmethyl phosphonofluoridate). Rapid and sensitive detection of these compounds is readily achieved by performing DESI from a solid surface; detection specificity is enhanced by implementation of a heterogeneous ion/molecule reaction using boric acid in the spray solvent. The reagent ion H~2~BO~3~^−^ generated in the spray readily reacts with condensed‐phase alkyl MPA to form anionic adducts. The specificity of this chemical reaction, together with the characteristic fragmentation patterns of the reaction products, supplies a highly discriminatory detection method for methylphosphonic acid (MPA), ethylphosphonic acid (EMPA) and isopropyl methylphosphonic acid (IMPA) in complex matrices. Copyright © 2007 John Wiley & Sons, Ltd.