CHARACTERIZATION OF EQUIMOLAR VX-WATER REACTION-PRODUCT BY CHROMATOGRAPHY MASS-SPECTROMETRY

One method proposed for the destruction of the chemical warfare nerve agent VX, O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothiolate, is hydrolysis by the addition of an equimolar amount of water. To bet ter understand this reaction, a method was developed for characterizat ion of the resulting product and for monitoring product stability. Con ditions for derivatization of the acidic products to their trimethylsi lyl esters, with subsequent analysis by gas chromatography-mass spectr ometry using electron (EI) and methane chemical ionization (CI) were o ptimized to allow nonchromatographable acids and organic products to b e detected in a single analysis, without loss of volatile products, an d with minimal side reaction. EI and methane CI mass spectra of 23 ide ntified degradation products are provided. Results indicate that the p roduct is relatively stable at ambient temperatures in a closed contai ner with only a minimal amount of thiol secondary reaction being obser ved. Published by Elsevier Science B.V.