Multiple Stable Isotope Characterization as a Forensic Tool to Distinguish Acid Scavenger Samples


  • Funding provided through contract HSHQDC-09-00037 to Pacific Northwest National Laboratory by the Department of Homeland Security Science and Technology Directorate.

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James Moran, Ph.D.
Chemical and Biological Signature Sciences
Pacific Northwest National Laboratory
999 Battelle Blvd, MSIN P7-50PO Box 999
Richland, WA 99352


Abstract:  Acid scavengers are frequently used as stabilizer compounds in a variety of applications. When used to stabilize volatile compounds such as nerve agents, the lower volatility and higher stability of acid scavengers make them more persistent in a post-event forensic setting. Compound-specific isotope analysis of carbon, nitrogen, and hydrogen in three acid-scavenging compounds (N,N-diethylaniline, tributylamine, and triethylamine) were used as a tool for distinguishing between different samples. Combined analysis of multiple isotopes improved sample resolution, for instance differentiation between triethylamine samples improved from 80% based on carbon alone to 96% when combining with additional isotope data. The compound-specific methods developed here can be applied to instances where these compounds are not pure, such as when mixed with an agent or when found as a residue. Effective sample matching can be crucial for linking compounds at multiple event sites or linking a supply inventory to an event.