Determination of nerve agent degradation products in environmental samples by liquid chromatography–time-of-flight mass spectrometry with electrospray ionization

A powerful and rapid method has been developed for the identification and quantitative determination of alkyl methylphosphonic acids, which are the degradation products of nerve agents, using liquid chromatography–time-of-flight mass spectrometry with electrospray ionization. Six alkyl methylphosphonic acids were well separated within 16 min. For quantitative analysis, good linearity, sensitivity and reproducibility were obtained by LC–MS in the selected ion monitoring mode. For unambiguous identification of alkyl methylphosphonic acids, fragment ions were produced by in-source collision induced dissociation (CID), and then exact mass measurement of CID fragment ions was performed. The feasibility of applying this technique for detecting these compounds in spiked environmental waters and soils was demonstrated.