Use of Alum Mixtures for Removal and Decontamination of VX and QL In Aqueous Solutions

摘要

Truly environmentally friendly means of detoxifying chemical warfare agents have yet to be developed. Toward this end, O-ethyl-S- 2 -(diisopropylamino) (ethyl) methylphosponothiolate (VX) and its precursor, O-ethyl- O's - (2-isopropylamino)ethyl methylphosphonite (QL), were treated with aqueous aluminum sulfate (alum), sodium aluminate, or mixtures of the two. The mixtures were prepared by combining varying volumes of the aqueous salts to give buffered solutions (pH 2-12). Reactions were tracked using phosphorus-31 nuclear magnetic resonance (NMR) and gas chromatography/mass spectrometry (GC/MS). Diazinon and malathion were also investigated. The focus here was on acidic buffers and un-buffered alum because VX and QL were not readily soluble in basic buffers, and because of evidence for the production of the extremely toxic sodium salt of S- 2-(diisopropylamino)ethyl methylphosphonothioic acid (EA- 2192) under basic conditions in the case of VX hydrolysis. Acidic alum and alum buffers hydrolyzed QL within a few minutes. NMR spectra of QL hydrolysate showed two to three broad peaks that are speculated to be different aluminum complexes of methylphosphinic acid based on proton coupled spectra. Acidic alum and alum buffers removed anywhere from 50% to 70% VX within the first twenty minutes from reaction mixtures in NMR tubes. No evidence of EA-2192 production was observed, and the main hydrolysis product, ethyl methylphosphonic acid, was also precipitated from solution. Studies with larger stoichiometric excesses of alum relative to agent are currently under way, but it appears that acidic alum and alum buffers may provide an effective alternate method for the destruction of QL and potentially VX as well.