Development and validation of a method for the analysis of organic explosive compounds by LC-MS/MS technique

The examination of explosive materials constitutes a fundamental research area within forensic laboratories, providing essential information for clarifying criminal incidents. Although cases involving explosives are less frequent than DNA profiling or narcotic analyses, their societal impact and legal consequences are significant. Accurate identification of explosives used in terrorist attacks and deliberate sabotage plays a critical role in maintaining evidence integrity and obtaining intelligence about the event. Evidence may include post-blast residues, recovered devices, and the primary and auxiliary components used in their manufacture. Consequently, explosive analysis is a specialized field requiring interdisciplinary knowledge, technical expertise, and high sensitivity and accuracy.In order to determine the type of explosive material used in an incident committed with a firearm after an explosion and to match it with previous incidents and to identify the perpetrator samples taken from explosive residues, environmental samples (water, soil, etc.) or from the suspect/victim and target should be analyzed using sensitive, fast and cheap analysis methods. In this study, a LC-MS-MS device with high sensitivity and selectivity was used to detect very low levels of TNT, HMX,RDX, PETN, TETRYL, 2.4-DNT, ETN and PA explosives used in caps and gunpowders in terrorist incidents today. In this study, samples were analyzed in positive and negative ionization modes using ESI ion source after a total of 30 min extraction procedure with a single-stage extraction. MEOH was used as the extraction solvent. MS/MS parameters and chromatographic method were optimized using gradient ammonium acetate: methanol mobile system and C18 column. Different solvents were tested for the extraction of target explosives from soil and MEOH solvent with the highest % recovery was found to be suitable. Validation parameters of the method we used for the analysis of explosive substances from soil were studied and finally the method was tested on soil samples taken from the actual explosion area. As a result, in this study, a fast, easy, selective, low observation and determination limit, high repeatability and recovery determination method was developed for TNT, RDX, HMX, TETRYL, PETN,2,4-DNT, ETN and PA in soil using LC-MS/MS.