Quantitative Analysis of Residual VX in Caustic Neutralization Solutions by Solid Phase Extraction and GC/MSD: Analysis of Hydrolysate as Separated Organic and Aqueous Phases

摘要

This report summarizes the methods development and validation efforts for the quantitation of the nerve agent 0-ethyl-S-2- (DIISOPROPYLAMINO)ETHYL methylphosphonothioate (VX) in caustic neutralization solutions. This method uses C2 solid phase extraction to trap VX from the caustic hydrolysate onto a solid sorbent. Several wash steps are employed to remove interferents from the solid sorbent bed. The VX is selectively eluted with dichloromethane, and the extract analyzed by gas chromatography with mass spectral detection. The overall method limit of detection was 57 and 1 nglmL (ppb) VX for the organic and aqueous phases, respectively. The overall precision (as percent relative standard deviation) was determined to be 9% for the organic phase, and 17% for the aqueous phase. The overall accuracy (as percent recovery) was determined to be 90% for the organic phase, and 86% for the aqueous phase.