Quantitative Analysis of Chemical Warfare Agent Degradation Products in Reaction Masses Using Capillary Electrophoresis

Abstract

Quantitative methods have been developed for the analysis of chemical warfare agent degradation products in reaction masses using capillary electrophoresis (CE). This is the first report of a systematic validation of a CE-based method for the analysis of chemical warfare agent degradation products in agent neutralization matrixes (reaction masses). After neutralization with monoethanolamine/water, the nerve agent GB (isopropyl methylphosphonofluoridate, Sarin) gives isopropyl methylphosphonic acid (IMPA) and O-isopropyl O'-(2-amino)ethyl methylphosphonate (GB-MEA adduct). The nerve agent GD (pinacolyl methylphosphonofluoridate, Soman), [pinacolyl = 2-(3,3-dimethyl)butyl] produces pinacolyl methylphosphonic acid (PMPA) and O-pinacolyl O'-(2-amino)ethyl methylphosphonate (GD-MEA adduct). The samples were prepared by dilution of the reaction masses with deionized water before analysis by CE/indirect UV detection or CE/conductivity detection. Migration time precision was less than 4.0% RSD for IMPA and 5.0 RSD for PMPA on a day-to-day basis. The detection limit for both IMPA and PMPA is 100 micrograms/L; the quantitation limit for both is 500 micrograms/L. For calibration standards, IMPA and PMPA gave a linear response (R2 = 0.9999) over the range 0.5-100 micrograms/mL. The interday precision RSDs were 1.9, 1.0, and 0.7% for IMPA at 7.5, 37.5 and 75.0 micrograms/mL, respectively. Corresponding values for PMPA (again, RSD) were 2.9, 1.1, and 1.0% at 7.5, 37.5 and 87.5 micrograms/mL, respectively, as before. Analysis accuracy was assessed by spiking actual neutralization samples with IMPA or PMPA. For IMPA, the seven spike levels used ranged from 20 to 220% of the IMPA background level, and the incremental change in the found IMPA level ranged from 86 to 99 % of the true spiking increment (R2 = 0.9987 for the linear regression). For PMPA, the five spike levels ranged from 10 to 150% of the matrix background level, and similarly, the accuracy obtained ranged from 95 to 97% of the true incremental value (R2 = 0.9999 for the linear regression).

Rapid identification of nerve agents Sarin (GB) and Soman (GD) with the use of a field-portable GC/SAW vapor detector and liquid desorption front-end device

“…A recent survey of the literature reveals that few field methods have been published for the rapid detection of these compounds at a suitably low threshold of detection. Current methods rely on GG/mass spectroscopy (GC/MS), immunoselective methods, or detection of degradation products, 4 which, like any analytical method, have some associated deficiencies. Current field-portable GC/MS instruments are somewhat bulky, and immunological methods require intensive wet chemical manipulation.…”

Separation and detection of VX and its methylphosphonic acid degradation products on a microchip using indirect laser-induced fluorescence

“…These features make microchips an attractive technology for rapid on-site detection and identification of CWA. Several groups reported on CE-based microfabricated devices for separation and detection of OP compounds [6], AChE inhibitors [7], degradation products of OP nerve agents [8,9], and explosives [6,10]. In a high pH or low pH aqueous medium, VX is degraded first to ethyl methylphosphonic acid (EMPA) and a thiol [3].…”

“…Determination of alkylphosphonic acids in aqueous solutions and in environmental matrixes was demonstrated in CE using indirect UV (IDUV) or conductivity detection [8,13,14]. The high persistency of VX and its degradation in environmental matrixes presents a challenge for simultaneous rapid separation and detection of VX, EMPA, and MPA.…”

Analysis of inorganic and small organic ions with the capillary electrophoresis microchip

“…Such devices may additionally serve as useful platforms for verifying the production and/or destruction of hazardous analytes, as well as in the collection of forensic evidence following terrorist attacks. The demonstrated capabilities of electrophoretic methods (capillary zone electrophoresis, CZE, and micellar electrokinetic chromatography, MEKC) in the detection of chemical warfare agent degradation products [18,19] explosives [20] and explosive related ions [21] illustrates the possibilities inherent with developing sensors using microfabricated CE chips. Traditional electrophoretic methods are additionally well suited to the analysis of hazardous metal ions and small organic ions in complex sample media [22][23][24].…”