Multiple-technique analytical characterization of a mixture containing chemical-weapons simulant from a munition

An amber yellow organic liquid was found in a munition shell at Dugway Proving Grounds, UT, USA, that was likely used as a simulant of chemical weapons. The primary analytical techniques to characterize the mixture were gas chromatography–infrared detection–mass spectral detection (GC–IR–MS); liquid chromatography–mass spectrometry (LC–MS); nuclear magnetic resonance (NMR) using the nuclei 1H, 13C and 31P; and gas chromatography–atomic emission detection (GC–AED). Six major phosphorus-containing components were identified and confirmed by at least three techniques, and several additional phosphorus-containing components of lower concentration have been identified by GC–IR–MS and LC–MS. Five major non-phosphorus components, including ethyl acetate, diethyl sulfide and dibutylamine, have been identified by multiple techniques. The major phosphorus compound (23.9±0.4 wt.%) was O,O,O-triethyl phosphorothioate (I) and the second most abundant (14.4±0.2 wt.%) was O,O,S-triethyl phosphorothioate (III). No VX, G-agent, or pesticide was observed in the sample, although III may be a cholinesterase inhibitor which produces delayed toxic response. III also produces a false hit for the pesticide cyanthoate when analyzed by GC–MS-EI. The mixture appears to have been formulated as a chemical warfare agent simulant, most likely as a challenge of agent detection techniques.