Analysis and Characterization of Smokeless Powders and Smokeless Powder Residues

Smokeless powders are a key element of modern ammunitions as well as a common energetic charge used in improvised explosive devices (IEDs), e.g. pipe bombs and pressure cooker IEDs. Smokeless powder particles, either unburned or partially burned, and burned smokeless powder residues (SPR) may be recovered following a shooting or explosive event. Smokeless powders and SPRs may be analyzed to establish chemical profiles based on the organic composition, which may then have the potential to differentiate samples. This analysis would allow for the establishment of a link between a known smokeless powder, e.g. sample from a suspect's home, and unknown smokeless powder, e.g. sample from a crime scene, thereby allowing for the identification of a potential smokeless powder source or connection between a suspect to a crime.

Gas chromatography - mass spectrometry (GC-MS) is a common, but time intensive, technique for smokeless powder analysis. Direct analysis in real time - mass spectrometry (DART-MS) offers a rapid analytical technique that may provide an alternative to GC-MS. A rapid technique could reduce case backlogs by offering greater throughput and increased efficiency. However, studies are necessary in which DART-MS is evaluated alongside traditional means of analysis, e.g. GC-MS, before DART-MS may be implemented in regular case work for smokeless powder analysis.

The primary objective of this research is to compare unburned smokeless powders to SPR, i.e. pre-burn to post-burn, to determine if there is a potential to connect the SPR to the pre-burn smokeless powder. The secondary objective of this research is to offer a critical comparison of GC-MS and DART-MS for smokeless powder and SPR analysis. The research will be completed in four major milestones. First, pre-burn smokeless powders will be analyzed and characterized via GC-MS and DART-MS to identify unique organic constituents. In the second phase, SPRs will be generated in lab to allow for the identification of compounds indicative of SPR via GC-MS and DART-MS.

Following in-lab experiments, real world shooting experiments will be conducted. Organic gunshot residue (OGSR) will be generated by firing of ammunition; firing experiments will be conducted in collaboration with the University of Central Florida Police Department. OGSR will then be characterized similarly to in-lab SPRs. Finally, chemometric methods will be applied to statistically determine the correlation between pre- and post-burn organic smokeless powder components.

"Note: This project contains a research and/or development component, as defined in applicable law," and complies with Part 200 Uniform Requirements - 2 CFR 200.210(a)(14).

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