Yu H A, DeTata D A, Lewis S W, Nic Daeid N
Department of Chemistry, Curtin University, GPO Box U1987, Perth 6845, WA, Australia; Nanochemistry Research Institute, Curtin University, GPO Box U1987, Perth 6845, WA, Australia; Centre for Anatomy and Human Identification, School of Science and Engineering, University of Dundee, UK.
Forensic Science Laboratory, ChemCentre, Manning Road, Bentley 6102, WA, Australia.
Talanta. 2017 Mar 1;164:716-726. doi: 10.1016/j.talanta.2016.07.001. Epub 2016 Jul 2.
Explosives residues in soils may be a useful source of evidence following the detonation of an improvised explosive device (IED), such as a vehicle-borne IED. Soil samples collected from the vicinity of an explosion scene will often be stored for some time prior to analysis, yet explosives residues in soil samples are susceptible to rapid degradation or transformation. Although some research has assessed the use of different storage temperatures with a view to reducing explosives' degradation over time, further research examining the degradation of explosives in soil when stored under a variety of storage conditions is crucial to determine the optimal sample collection and storage procedures for soil containing explosives residues. In this work, three different soils were spiked with solutions of TNT, RDX and PETN and stored either at room temperature, refrigerated or frozen. Samples were extracted over 6 weeks, with additional samples gamma-irradiated or nitrogen purged prior to storage. Experimental results indicate that TNT underwent very rapid degradation at room temperature, attributed to microbial action, whereas PETN and RDX proved to be more stable. Gamma irradiation and nitrogen purging proved of some benefit for mitigating TNT degradation, with lower storage temperatures ultimately proving the most effective method of mitigating degradation.
简易爆炸装置（IED），如车载简易爆炸装置引爆后，土壤中的爆炸物残留物可能是有用的证据来源。从爆炸现场附近采集的土壤样本在分析前通常会储存一段时间，但土壤样本中的爆炸物残留物容易迅速降解或转化。尽管一些研究评估了使用不同储存温度以减少爆炸物随时间的降解情况，但进一步研究在各种储存条件下储存时土壤中爆炸物的降解情况对于确定含有爆炸物残留物的土壤的最佳样本采集和储存程序至关重要。在这项工作中，三种不同的土壤分别加入了TNT、RDX和PETN溶液，并分别在室温、冷藏或冷冻条件下储存。样本在6周内进行提取，另外一些样本在储存前进行了伽马辐照或氮气吹扫。实验结果表明，由于微生物作用，TNT在室温下迅速降解，而PETN和RDX则更稳定。伽马辐照和氮气吹扫被证明对减轻TNT降解有一定益处，最终证明较低的储存温度是减轻降解的最有效方法。
