ethyl-methylphosphonic-acid and pentafluorobenzoic-acid

In the work reported here, a screening procedure was developed for the detection and identification of RMPAs (nerve agent degradation products) after pentafluorobenzylation using liquid chromatography-tandem mass spectrometry (LC-MS/MS). With this method, all RMPAs, including highly hydrophilic types such as methylphosphonic acid (MPA) and ethyl methylphosphonic acid (EMPA), were sufficiently retained in commonly used reversed-phase columns (retention times: 15.7 and 11.0 min.), and the presence of RMPAs was determined more efficiently than with the conventional direct LC-MS/MS method. The detection limits of RMPAs using this approach (<33 ng) were mostly superior to those observed with direct LC-MS/MS (<74 ng) and gas chromatography-mass spectrometry (GC-MS) after pentafluorobenzylation (<1.1 μg). The applicability of newly developed method toward real samples was evaluated via recovery tests involving urine/serum and wipe tests on various surfaces.

Topics: Benzoates; Blood Chemical Analysis; Chemical Warfare Agents; Chromatography, Liquid; Gas Chromatography-Mass Spectrometry; Humans; Hydrophobic and Hydrophilic Interactions; Limit of Detection; Nerve Agents; Organophosphonates; Organophosphorus Compounds; Tandem Mass Spectrometry; Urinalysis