Identification of post-blast explosive residues using direct-analysis-in-real-time and mass spectrometry (DART-MS)

Abstract

Application of Direct-Analysis-in-Real-Time (DART) ionization with mass spectrometry (DART-MS) to identify homemade explosive (HME) residue recovered from genuine post-blast bomb fragments is presented. A variety of simulated improvised explosive devices (IEDs) were configured to replicate post-blast debris representative of materials encountered in real forensic casework scenarios. Peroxide-based HME was used as explosive filler: triacetone triperoxide (TATP), hexamethylene triperoxide diamine (HMTD) and methyl ethyl ketone peroxide (MEKP). Each IED was fired separately and the recovered fragments analyzed using full scan with high-resolution mass spectrometry. Fragments were analyzed directly and indirectly using cotton swabs and the target explosive was detected using either sampling technique. This work demonstrates the forensic validity of DART-MS to provide rapid and quality-assured identification of explosive residues from real post-blast IED fragments.