Extraction of Chemical Warfare Agents from Soils: Case Study on O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothiolate (VX)

Abstract

Extraction of chemical warfare agents, O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothiolate (VX) in soilsample has been carried out. The extraction was performed using six different solvents including 1% TEA/MeOH, 1% NH 4 OH/MeOH, water pH 2 at the ambient temperature , water pH 2 at temperature 4 0 C, water pH 7 at ambient temperature, and water pH 7 at temperature 4 0 C. Percent recovery of VX in soil samples was quantitatively determined by mean LC-MS using selected reaction monitoring (SRM). Among the solvents used, water pH 2 at temperature 4 0 C gave the best extraction capability that was indicated by the highest percent recovery of VX obtained. Storing effect of spiked samples was also investigated by extracting the samples containing VX using water at pH 2/4 0 C and the degradation product was then identified using multiple reaction monitoring (MRM). From the study, two degradation products were identified as Bis[2-(diisopropylamino)ethyl]disulphide and ethyl methylphosphonate.

Evidence of VX nerve agent use from contaminated white mustard plants

“…The pH of loam and sandy soils was 6.5, while the pH of the clay soil was 9.0. The pH of the sandy soil was similar to a literature value [28].…”