Generic Rapid Analysis of Current and Prospective Nerve Agents and Their Degradation Products

We have developed a rapid and highly reliable analytical methodology for current and prospective nerve agents and their degradation products. The approach is to augment existing analytical methods with a specific enzymatic transformation step. It utilizes a novel bacterial phosphonate ester hydrolase enzyme (PEH), which degrades the agents’ alkali hydrolysis phospho-products (h-agents) to alkylphosphonic acids. Combined with current analytical protocol, which involves testing both the neat and alkali treated sample, the process would generate three distinct phospho-analytes for each agent. Thus, the unique “fingerprint” produced would enable rapid screening and identification of current and prospective nerve agents and their phospho-products using existing instrumental methods (e.g., GC-FPD, GC-PFPD, LC/MS, GC/MS, and GC/MS/MS). For example, we used GC-FPD to ferret out the presence of potential h-agents in samples that were contaminated with other phospho-compounds. This was possible because of the telltale retention time shifts on the chromatograms as the result of the PEH hydrolytic activity. Two critical issues concerning the methodology were addressed in this study: the effectiveness of the alkali to hydrolyze current and prospective nerve agents and the ability of PEH to further degrade the resulting phosphonate esters. All five nerve agents and nine commercially obtained dialkyl alkylphosphonates tested were converted to their respective alkyl alkylphosphonate esters by alkali treatment. This demonstrates the effectiveness of alkali, since the dialkyl alkylphosphonates are assumed to possess much stronger ester bonds than are expected in the leaving groups of any prospective nerve agent. Also, all twenty-six monoalkyl alkylphosphonates tested were effectively degraded by PEH, including those obtained from the above mentioned alkali treatment. The study demonstrates that this new methodology would be an effective analytical approach for current and prospective nerve agents and their phosphoproducts. Report Documentation Page Form Approved OMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 01 OCT 2005 2. REPORT TYPE N/A 3. DATES COVERED 4. TITLE AND SUBTITLE Generic Rapid Analysis Of Current And Prospective Nerve Agents And Their Degradation Products 5a. CONTRACT NUMBER