Institut National de Criminalistique et Criminologie, Bruxelles, Belgium.
Institut de Recherche Criminelle de la Gendarmerie National, Pontoise, France.
Forensic Sci Int. 2020 Apr;309:110183. doi: 10.1016/j.forsciint.2020.110183. Epub 2020 Feb 13.
A round-robin test on the identification of GSR particles by SEM/EDX and involving eleven Institutes was conducted on a real sample, in order to evaluate the possibilities/limitations of using such sample to get additional information (compared to the analysis of the usual synthetic sample used within the framework of the ENFSI proficiency test) about the performances of the SEM/EDX systems. Each Institute was asked to analyse this sample following its own standard operating procedure, and by using all the systems in house, whenever available. Between each Institute, a check of the sample was performed by the organizing Institute (NICC), in order inter alia to monitor any degradation and/or contamination of the sample. A total of about 30 analyses were performed on the sample. For each particle of interest identified on the real sample, the detection effectiveness was monitored, as well as the classification allotted by each Institute. The Institutes were also asked to report some of their measurement parameters, and to send the results as they would have been communicated in their own case report. A quite good agreement was observed with regard to the classification of the particles of interest, since a broad consensus was reached for approximately 75% of these particles. A different classification risk exists for some classes, the barium/antimony classes being probably the most critical, as traces of lead may cause the particles to shift (or not) from the consistent with GSR upper-class to the characteristic of GSR upper-class; in the end, the decision to shift from one class to another strongly depends on local rules. At the end of the campaign, a survey sent to collect experience and lessons learned from this exercise showed that analysing a real sample definitively offers an added value, especially in terms of classification process (during the automatic run and when performing the manual review) of particles.
一项涉及 11 个研究所的关于 SEM/EDX 识别 GSR 颗粒的轮次测试在一个实际样本上进行，目的是评估使用此类样本（与在 ENFSI 能力测试框架内分析常用合成样本相比）获得有关 SEM/EDX 系统性能的额外信息的可能性/局限性。每个研究所都被要求按照自己的标准操作程序，并且只要有可能，使用所有内部系统来分析该样本。在每个研究所之间，组织研究所（NICC）对样本进行了检查，以监测样本的任何降解和/或污染。总共对样本进行了大约 30 次分析。对于在实际样本上识别出的每个感兴趣的颗粒，监测了其检测效果，以及每个研究所分配的分类。还要求研究所报告他们的一些测量参数，并将结果按照他们在自己的案例报告中报告的方式发送。在分类感兴趣的颗粒方面观察到了相当好的一致性，因为大约 75%的颗粒达成了广泛共识。对于某些类别，存在不同的分类风险，钡/锑类别可能是最关键的，因为铅痕迹可能导致颗粒从与 GSR 上类别一致转移（或不转移）到 GSR 上类别的特征；最终，从一个类别转移到另一个类别的决定强烈取决于当地规则。在活动结束时，一项旨在收集该练习经验教训的调查显示，分析实际样本确实具有附加值，尤其是在颗粒的分类过程（在自动运行和执行手动审查期间）方面。
