Comparing the Additive Composition of Smokeless Gunpowder and Its Handgun-fired Residues

Abstract

Detecting the use of handguns via the determination of the organic additives in smokeless gunpowder residues (OGSR) presents a promising alternative to primer metal residue analysis. Compositional analysis of the gunpowder additives nitroglycerin, diphenylamine, and ethyl centralite provides information that can associate residue samples with unfired gunpowder. We evaluated the composition of seven reloading smokeless gunpowders, both in bulk and as single particles, by ultrasonic solvent extraction/capillary electrophoresis. Handgun-fired residues obtained from three common weapon calibers loaded with the known reloading powders were compared with the unfired powders. In general, the composition of the residues was similar to that found in the unfired powders. For double-base powders, comparing the ratio of the propellant (P) to the total amount of stabilizer (S) for both residue and gunpowder samples proved to be a useful measurement for identification. This P/S ratio demonstrated that the additives in the residues did not greatly change relative to the unfired powder, providing a useful indicator to aid in forensic powder and residue evaluation.

Recent developments in methods of chemical analysis in investigations of firearm-related events

“…MacCrehan et al [56,57,88,89,90,91,92] used MECE for analysis and comparison of fired and unfired propellants. Procedures for recovery of gunpowder residue components under a variety of sampling conditions were evaluated and improved for MECE analysis.…”

Advances of capillary electrophoresis in clinical and forensic analysis (1999-2000)

“…MacCrehan and co-workers have pioneered the development of CE for the detection of organic gunshot residue and smokeless powders. In a series of papers they have demonstrated the applicability of CE for the detection of smokeless powder residue from pipe bombs [41], and gunshot residue [42][43][44]. These papers consist of a series of different validation studies of the analysis of smokeless powders.…”

A Method for the Differentiation of Single-Base and Double-Base Smokeless Powders using the Hanging Drop Technique

“…Smokeless powders are traditionally analyzed in a laboratory setting and require timeconsuming protocols and expensive confirmatory instrumentation. Previous studies cite the use of gas chromatography-mass spectrometry (GC-MS), high performance liquid chromatography (HPLC), ion chromatography, and micellar electrokinetic capillary electrophoresis [5][6][7][8][9][10]. Though the confirmatory result is advantageous, the potential drawbacks for many laboratories are a drain on the economic and time resources.…”