Benson Sarah, Lennard Chris, Maynard Philip, Roux Claude
Forensic Services, Australian Federal Police, Canberra, ACT.
Forensic Sci Int. 2006 Feb 10;157(1):1-22. doi: 10.1016/j.forsciint.2005.03.012.
The key role of a forensic scientist is to assist in determining whether a crime has been committed, and if so, assist in the identification of the offender. Many people hold the belief that a particular item can be conclusively linked to a specific person, place or object. Unfortunately, this is often not achievable in forensic science. In performing their role, scientists develop and test hypotheses. The significance of those hypotheses that cannot be rejected upon completion of all available examinations/analyses is then evaluated. Although one can generally identify the substances present using available techniques, it is generally not possible to distinguish one source of the same substance from another. In such circumstances, although a particular hypothesis cannot be rejected, it cannot be conclusively proven, i.e. the samples could still have originated from different sources. This limitation of not being able to distinguish between sources currently extends to the analysis of other forensic samples including, but not limited to, ignitable liquids, paints, adhesives, textile fibres, plastics, and illicit drugs. Stable isotope ratio mass spectrometry (IRMS) is an additional technique that can be utilised to test a given hypothesis. This technique shows the potential to be able to individualise a range of materials of forensic interest. This paper provides a brief description of the technique, followed by a review of the various applications of IRMS in different scientific fields. The focus of this summary is on forensic applications of IRMS, in particular the analysis of explosives, ignitable liquids and illicit drugs.
法医科学家的关键作用是协助确定是否发生了犯罪行为，如果发生了犯罪行为，则协助识别犯罪者。许多人认为某一特定物品可以确凿地与特定的人、地点或物体联系起来。不幸的是，在法医学中这往往是无法实现的。在履行职责时，科学家们会提出并检验假设。然后对在完成所有可用的检验/分析后不能被否定的那些假设的重要性进行评估。虽然一般可以使用现有技术识别存在的物质，但通常不可能区分同一物质的不同来源。在这种情况下，虽然某个特定假设不能被否定，但也不能得到确凿的证明，即样本仍可能来自不同的来源。目前，这种无法区分来源的局限性也适用于其他法医样本的分析，包括但不限于可燃液体、油漆、粘合剂、纺织纤维、塑料和非法药物。稳定同位素比率质谱法（IRMS）是一种可以用来检验给定假设的附加技术。这项技术显示出能够对一系列具有法医意义的材料进行个体化分析的潜力。本文简要介绍了该技术，随后回顾了IRMS在不同科学领域的各种应用。本综述的重点是IRMS的法医应用，特别是爆炸物、可燃液体和非法药物的分析。
