New data for analyze improvised explosives in forensic practice

Abstract

Improvised explosives can be, in most cases, prepared from relatively easily accessible matters. The preparation procedure is often simple and generally known, or the information can be looked up on the Internet. The spectrum of phases which can be met concerning these materials is extremely wide and until now no systematic attention has been paid to this fact. In the past years the attention of the Institute of Criminalistics and the University of Pardubice concentrated on preparation of selected groups of these matters, to experimental explosions and to analyses of primary phases and post blast residues using wide spectrum of analytical techniques. Last year the organic analysis was focused on the detection of amines. A simple and sensitive method for the determination of free aliphatic and aromatic amines using derivatives agents as a labelling reagent by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) has been developed. Derivatization conditions including reagent concentration, buffer pH, reaction time and temperature were optimized. A fluorescence derivatization - high-performance liquid chromatography (HPLC) method, which enables the femtomole-level detection of analytes, is a powerful tool for the analysis with high sensitivity and selectivity. Inorganic microanalysis was concentrated on analysis of post-blast residues from experimental explosions of explosive pyrotechnical compositions based on potassium nitrate, sodium nitrate, and barium nitrate – fuel. All the information obtained is stored in a specialized software – database, which will be used by specialized security units. All the activities described above are still in progress.