Chemical analysis of bleach and hydroxide-based solutions after decontamination of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX)

Abstract

Detailed chemical analysis of solutions used to decontaminate chemical warfare agents can be used to support verification and forensic attribution. Decontamination solutions are amongst the most difficult matrices for chemical analysis because of their corrosive and potentially emulsion-based nature. Consequently, there are relatively few publications that report their detailed chemical analysis. This paper describes the application of modern analytical techniques to the analysis of decontamination solutions following decontamination of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX). We confirm the formation of N,N-diisopropylformamide and N,N-diisopropylamine following decontamination of VX with hypochlorite-based solution, whereas they were not detected in extracts of hydroxide-based decontamination solutions by nuclear magnetic resonance (NMR) spectroscopy or gas chromatography-mass spectrometry. We report the electron ionisation and chemical ionisation mass spectroscopic details, retention indices, and NMR spectra of N,N-diisopropylformamide and N,N-diisopropylamine, as well as analytical methods suitable for their analysis and identification in solvent extracts and decontamination residues.

Analysis of Organophosphorus-Based Nerve Agent Degradation Products by Gas Chromatography-Mass Spectrometry (GC-MS): Current Derivatization Reactions in the Analytical Chemist’s Toolbox

“…To this end, alternative methods that can accomplish the destruction of OPNAs while minimizing their hydrolytic and oxidative reaction towards the environment have been foci of intense research efforts. Some of these methods include the use of metal-based catalysts that can operate in catalytic fashion at low basic pH ranges [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ], hydrogen peroxide-based solutions that are not as corrosive as bleach [ 35 , 36 , 37 ], and metal oxide-based approaches (e.g., FeO, Fe 2 O 3 , Al 2 O 3 , MgO) [ 38 , 39 , 40 , 41 ] that also degrade the OPNA via oxidative degradation pathways. Another area of research that has yielded unique methods for the degradation of OPNAs is in the materials sciences, efforts that have yielded technologies such as metal organic frameworks (MOFs) [ 20 , 42 , 43 ] and the aforementioned second skin technologies [ 20 , 21 ] that can find significant application in the field by providing a strong protective layer to the warfighter.…”

Colloidal gel as an efficient process to treat Chemical, Biological, Radiological (CBR) and prion contaminated solid surfaces

“…However, since sulfur is oxidized in the presence of hypochlorite ions, this should facilitate cleavage of the P-S bond [16]. Recently indeed, VX has successfully been degraded in hypochlorite solutions into non-toxic N,N-diisopropylformamide and N,N-diisopropylamine [35]. This mechanism is consistent with the higher degradation efficiency obtained with fresh CBR gel compared to fresh NaOH-gel, which have the same NaOH concentration, because of the presence of hypochlorite ions in the fresh CBR gel.…”

Toxicity and medical countermeasure studies on the organophosphorus nerve agents VM and VX

“…(i) 14 C VM This was 98% pure by 1 H, and 99% pure by 31 P, NMR spectroscopy. 1 Labelled and unlabelled samples of the V-agents were confirmed analytically pure by mass spectrometry techniques that are reported elsewhere [19][20][21][22][23][24]. These are accredited under ISO/IEC 17 025 : 2005 and used routinely within the UK's OPCW Designated Laboratory at Dstl Porton Down.…”