Identification of peroxide explosives and traditional explosive anions by capillary electrophoresis

Scope and Method of Study. Terrorists choose to use peroxide explosives such as triacetone triperoxide (TATP) in improvised explosive devices (IEDs) for the devastating explosive power offered and simple procurement as compared to traditional explosives. Peroxide explosive residues are an analytical challenge due to their volatility, as well as their simple structure which lacks distinctive metallic and ionic signatures.;The analysis of traditional explosive residues can be a difficult task for the forensic chemist, with many methods to choose from on a wide variety of instruments. Rather than providing definitive answers, the results are used by investigators to infer the types of explosives present. Due to the diverse nature of explosives, it is unusual to find a single method that will analyze for multiple types of explosives without the use of several extractions or instruments.;The purpose of this study is to describe the analysis of peroxide explosives through capillary electrophoresis (CE) with a traditional borate buffer. This is the first known instance in which an analytical method can screen for peroxide explosives (TATP) along with anions commonly associated with low explosives. This analysis is simultaneous and does not require the use of separate methods and preparations.;Findings and Conclusions. A literature method for low explosive anions analysis by CE was optimized for use and the relative migration times (RMT) for nine common anions were determined. All precursors for peroxide explosive manufacture were analyzed and RMTs of significant peaks were identified. TATP standards were characterized by four peaks in the electropherogram, and all significant precursor peaks were eliminated as contributors to these peaks. Post-blast residue swabs and burn sticks extracted in methanol were analyzed by gas chromatography-mass spectrometry to confirm the presence of TATP, and then TATP was identified in the extract by CE through the comparison of RMTs. The method produced repeatable RMTs with minimal overlap between selected ions, precursor compounds, and TATP signature peaks.