Forensic analysis of nitroglycerin in post blast samples

Abstract

Forensic analysis of explosive in post blast samples maygive valuable information regarding the type, thequantity, the source and the person that may be involvedin explosion cases. The presence of nitroglycerin in postblast samples is indicative of double base propellant usedas explosives in improvised devices (IEDs). In asimulated explosion case, PVC pipe bombs filled withvarying amounts of double base propellant weredeflagrated and fragments collected. Fragments wereanalyzed via the presence of nitroglycerin (NG). NG wasanalyzed using high performance liquid chromatography(HPLC) with ultra violet detection. Analyte wasseparated on a reversed-phase C18 column employingacetonitrile-water (60:40) mixture as the mobile phaseand analyte detection at 210 nm. The calibration curve of NG gave good correlation coefficient (0.998) and goodlimit of detection (20 ng). Post blast fragment of pipebombs were found to be scattered behind the barriersandbags in a hemispherical shape within a radius of 25m. For both explosions utilizing 100 g and 200 g of explosive charge, the fragmented caps of pipe bombsdisplayed the highest amount of NG. Results of this studyalso revealed that higher amount of explosive residues inthe blast seat were obtained with increasing amount of charged explosive used.