Enzymatic Analysis of G- and V-Agents and Their Degradation Products; Conference paper

摘要

We are presenting a rapid and highly reliable analytical methodology for nerve agents and their degradation products. The approach is to augment existing analytical methods with the specificity of the enzymatic degradation of the agents and their phosphonate ester products. The nerve agents can be hydrolyzed to their respective methylphosphonate alkyl ester (h-agent) products by alkali treatment or by specific hydrolytic enzymes, such as organophosphorus hydrolase (OPH) and organophosphorus acid anhydrolase (OPAA). A bacterial phosphonate ester hydrolase enzyme (PEH) would further degrade hagents to methylphosphonic acid (MPA). The methodology is based on using these specific enzymes in two different schemes: 1) rapid screening for MPA (e.g. MS/MS) after the sample treatment with all three enzymes and 2) thorough analysis of the agent by creating a unique fingerprint from each agent through the appropriate enzymatic treatment. Initially, the agent would be identified and quantified (e.g. GC-FPD) from the fingerprint consisting of the original agent and silylated enzymatic degradation products, h-agent and MPA, by comparing the unique retention times of each analyte. The agents and their products can be further interrogated by the existing instrumental methods (e.g., LC/MS, GC/MS, and GC/MS/MS) for their eventual identification. Furthermore, since PEH can degrade alkyl and aryl esters of other phosphonates besides MPA esters, approach can be expanded to develop the capability to analyze potential novel threat OP CWAs and their degradation products. For this purpose, we are currently developing databases of the GC-FPD and GC/MS profiles for selected alkyl phosphonic acids and their alkyl esters.