Forensic analysis of explosives using isotope ratio mass spectrometry (IRMS) - discrimination of ammonium nitrate sources
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Date
2009-06
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
An evaluation was undertaken to determine if isotope ratio mass spectrometry (IRMS) could assist in the investigation of complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques. The focus of the research was on ammonium nitrate (AN), a common oxidiser used in improvised explosive mixtures. The potential value of IRMS to attribute Australian AN samples to the manufacturing source was demonstrated through the development of a preliminary AN classification scheme based on nitrogen isotopes. Although the discrimination utilising nitrogen isotopes alone was limited and only relevant to samples from the three Australian manufacturers during the evaluated time period, the classification scheme has potential as an investigative aid. Combining oxygen and hydrogen stable isotope values permitted the differentiation of AN prills from three different Australian manufacturers. Samples from five different overseas sources could be differentiated utilising a combination of the nitrogen, oxygen and hydrogen isotope values. Limited differentiation between Australian and overseas prills was achieved for the samples analysed. The comparison of nitrogen isotope values from intact AN prill samples with those from post-blast AN prill residues highlighted that the nitrogen isotopic composition of the prills was not maintained post-blast; hence, limiting the technique to analysis of un-reacted explosive material. © 2009, Elsevier Ltd.
Description
Keywords
Stable isotopes, Ammonium nitrates, Explosives, Isotope ratio, Mass spectroscopy, Crime detection
Citation
Benson, S. J., Lennard, C. J., Maynard, P., Hill, D. M., Andrew, A. S., & Roux, C. (2009). Forensic analysis of explosives using isotope ratio mass spectrometry (IRMS) - discrimination of ammonium nitrate sources. Science & Justice, 49(2), 73-80. doi:10.1016/j.scijus.2009.04.005