Discrimination of smokeless powders by headspace SPME-GC-MS and SPME-GC-ECD, and the potential implications upon training canine detection of explosives

Abstract

This presentation will provide an odour analysis of a variety of smokeless powders & communicate the rapid SPME-GC-ECD method utilized. This paper will also discuss the implications of the headspace analysis of Smokeless Powders upon the choice of training aids for Explosives Detection Canines.Canine detection of explosives relies upon the dogs' ability to equate finding a given explosive odour with a reward, usually in the form of praise or play. The selection of explosives upon which the dogs are trained thus determines which explosives the canines can and potentially cannot find. Commonly, the training is focussed towards high explosives such as TNT and Composition 4, and the low explosives such as Black and Smokeless Powders are added often only for completeness. Powder explosives constitute a major component of explosive incidents throughout the US, and canines trained to detect explosives must be trained across the entire range of powder products. Given the variability in the manufacture and product make-up many smokeless powders do not share common odour chemicals, giving rise to concerns over the extensiveness of canine training. Headspace analysis of a selection of Smokeless Powders by Solid Phase Microextraction GasChromatography using Mass Spectrometry (SPME-GC-MS) and Electron Capture Detectors (SPME-GC-ECD) has highlighted significant differences in the chemical composition of the odour available from different brands. This suggests that greater attention should be paid towards the choice of Powder Explosives when assigning canine training aids.

Characterization of an odor permeable membrane device for the storage of explosives and use as canine training aids

“…Based on their work in identifying the volatile compounds that are emitted from explosives, Furton et al introduced COMPS (Controlled Odor Mimic Permeation System) [8–11]. This system was based on diffusion/permeation of volatiles through heat‐sealed low‐density polyethylene bags.…”

Vapor Signatures of Double-Base Smokeless Powders and Gunshot Residues for Supporting Canine Odor Imprinting

“…Because there are hundreds of smokeless powder compositions, it is intuitive to anticipate gunshot residues (GSRs) to be similarly variable. The headspace of GSRs is expected to contain many of the same compounds as unburnt powder, ,− but the overall vapor signatures will be altered by degradation (e.g., from environmental exposure and the firing process) and how the firearm has been handled (e.g., how frequently the firearm is cleaned and used). There are anecdotal accounts from canine trainers that the performance of a canine can decrease for old GSRs, which may be attributed to decreasing vapor concentrations and altering vapor compositions over time.…”

“…This study used a triple-quadrupole mass spectrometer with a custom ionization source to directly measure vapor emanation from the sample . The system in this study differs from many past MS measurements by (1) not requiring vapor sampling like SPME-GC/MS, ,,,, (2) not requiring liquid extraction of the solid sample, , (3) not heating the sample, and (4) not requiring a sample desorption step like thermal desorption or desorption electrospray ionization (DESI). All measurements herein focused on naturally emanating vapor and were conducted in real-time under ambient conditions (∼20 °C).…”

Intermolecular Interactions between Eosin Y and Caffeine Using1H-NMR Spectroscopy

“…A quick, sensitive, and selective detection system is required for many applications, such as alerting security officers to the presence of explosives or their precursors, preincident monitoring/screening for homeland security purposes [1] such as weapons of mass destruction, and detection and quantification of doping compounds in competitive sports [2–5]. The method that is currently most widely used for the detection of such substances is gas chromatography-mass spectrometry (GC-MS) [6, 7]. However this method requires a skilled operator and cannot be easily miniaturized.…”