Institut de Police Scientifique, Ecole des Sciences Criminelles, Université de Lausanne, Lausanne-Dorigny, Switzerland.
Forensic Sci Int. 2010 Jan 30;194(1-3):115-24. doi: 10.1016/j.forsciint.2009.10.024. Epub 2009 Dec 2.
In arson cases, the collection and detection of traces of ignitable liquids on a suspect's hands can provide information to a forensic investigation. Police forces currently lack a simple, robust, efficient and reliable solution to perform this type of swabbing. In this article, we describe a study undertaken to develop a procedure for the collection of ignitable liquid residues on the hands of arson suspects. Sixteen different collection supports were considered and their applicability for the collection of gasoline traces present on hands and their subsequent analysis in a laboratory was evaluated. Background contamination, consisting of volatiles emanating from the collection supports, and collection efficiencies of the different sampling materials were assessed by passive headspace extraction with an activated charcoal strip (DFLEX device) followed by gas chromatography-mass spectrometry (GC-MS) analysis. After statistical treatment of the results, non-powdered latex gloves were retained as the most suitable method of sampling. On the basis of the obtained results, a prototype sampling kit was designed and tested. This kit is made of a three compartment multilayer bag enclosed in a sealed metal can and containing three pairs of non-powdered latex gloves: one to be worn by the sampler, one consisting of a blank sample and the last one to be worn by the person suspected to have been in contact with ignitable liquids. The design of the kit was developed to be efficient in preventing external and cross-contaminations.
在纵火案件中，收集和检测嫌疑人手上的可燃液体痕迹可以为法医调查提供信息。警方目前缺乏一种简单、强大、高效和可靠的方法来进行这种擦拭取样。本文介绍了一项旨在开发一种收集纵火嫌疑手上可燃液体残留物的程序的研究。考虑了 16 种不同的采集支持物，并评估了它们在手和随后在实验室中分析存在的汽油痕迹的适用性。通过使用活性炭带（DFLEX 装置）进行被动顶空提取，并随后进行气相色谱-质谱（GC-MS）分析，评估了不同采样材料的背景污染（由采集支持物散发的挥发性物质组成）和采集效率。对结果进行统计处理后，非粉末乳胶手套被保留为最适合的采样方法。在此基础上，设计并测试了一个原型采样套件。该套件由一个三层多层袋组成，装在一个密封的金属罐中，内有三副非粉末乳胶手套：一副供采样员使用，一副为空白样品，最后一副供疑似接触过可燃液体的人员使用。套件的设计旨在有效防止外部和交叉污染。
