posted on 2006-06-15, 00:00authored byIshay Columbus, Daniel Waysbort, Liora Shmueli, Ido Nir, Doron Kaplan
The fate of the persistent OP nerve agent O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX) on
granular activated carbons that are used for gas filtration
was studied by means of 31P magic angle spinning
(MAS) NMR spectroscopy. VX as vapor or liquid was
adsorbed on carbon granules, and MAS NMR spectra were
recorded periodically. The results show that at least
90% of the adsorbed VX decomposes within 20 days or
less to the nontoxic ethyl methylphosphonic acid (EMPA)
and bis(S-2-diisopropylaminoethane) {(DES)2}. Decomposition
occurred irrespective of the phase from which VX was
loaded, the presence of metal impregnation on the carbon
surface, and the water content of the carbon. Theoretical
and practical aspects of the degradation are discussed.