High-throughput screening for target compounds in smokeless powders using online-SPE tandem mass spectrometry

Towards more relevance in forensic science research and development

Many different issues have been identified in forensic science for more than 10 years. While quality management has often been suggested as a path forward, research is generally considered as an essential part of the solution. Through an overview of current forensic science research, this paper aims at evaluating if and how research answer the challenges forensic science is currently facing. While forensic related publications have massively increased over the years, approximately half of the publications were published in non-forensic sources, indicating that forensic science research tends to be led by other disciplines. Over the years, forensic science research has remained largely oriented towards methodological and technological development rather than relevance to the forensic science discipline and practice. Practical implementation of the techniques is rarely discussed from a forensic perspective, and thus research rarely move from the "proof-of-concept" stage to its utilisation in case investigation. The digital transformation also generated a massive increase of data, making it challenging to find the relevant pieces of information in the mass of "forensic" publications available on-line. Thus, we propose to refocus forensic science research on forensic fundamental and practical questions to strengthen the discipline and its impact on crime investigation and security issues. Our propositions represent an incentive to further discuss forensic science research and knowledge transmission through the definition of a common culture within the community, focusing on common fundamental knowledge such as a better understanding of the concept of trace and its case-based information content.

Quantitative analysis of smokeless powder particles in post‐blast debris via gas chromatography/vacuum ultraviolet spectroscopy ( GC / VUV )

Forensic analysis of smokeless powder particles recovered from the debris of an improvised explosive device can provide information about the type of smokeless powder used and can aid investigation efforts. In this study, quantitative methods were used to yield information about the difference in the chemical composition of the particles pre‐ and post‐blast. The technique, gas chromatography/vacuum ultraviolet spectroscopy (GC/VUV), was able to quantify nitroglycerin, 2,4‐dinitrotoluene, diphenylamine, ethyl centralite, and di‐n‐butyl phthalate in pre‐ and post‐blast smokeless powder particles using heptadecane as an internal standard. Post‐blast debris was obtained via controlled explosions with assistance from the Indiana State Police Bomb Squad. Two galvanized steel and two polyvinyl chloride pipe bombs were assembled. Two devices contained single‐base smokeless powder and two contained double‐base smokeless powder. 2,4‐dinitrotoluene and diphenylamine were successfully quantified in the single‐base smokeless powder post‐blast debris while nitroglycerin, diphenylamine, and ethyl centralite were successfully quantified in the double‐base smokeless powder post‐blast debris. Compounds were detected at concentrations as low as 9 μg of 2,4‐dinitrotoluene per mg, <3 μg of diphenylamine per mg, 131 μg of nitroglycerin per mg, and <3 μg of ethyl centralite per mg. Concentration changes between pre‐ and post‐blast smokeless powder particles were determined as well as microscopic differences between pre‐ and post‐blast debris for both smokeless powders in all devices. To our knowledge, this is the first use of GC/VUV for the quantification of explosives.

Towards Safer Primers: A Review

Primers are used to reliably initiate a secondary explosive in a wide range of industrial and defence applications. However, established primer technologies pose both direct and indirect risks to health and safety. This review analyses a new generation of primer materials and ignition control mechanisms that have been developed to address these risks in firearms. Electrically or optically initiated metal, oxide and semiconductor-based devices show promise as alternatives for heavy metal percussive primers. The prospects for wider use of low-cost, safe, reliable and non-toxic primers are discussed in view of these developments.