Abstract Condom evidence can be analysed using several analytical techniques, such as FTIR, MALDI-MS or DART-TOF-MS, but the only one that was used on real samples for transfer and persistence studies in the context of sexual assault or rape cases was Py-GC/MS. However, there has been no study to identify which specific pyrolysis parameters were the most suitable for the analysis of silicone-based lubricants, especially in terms of repeatability of the analyses. This study looked at the different reported pyrolysis parameter with the aim of optimizing these parameters for polydimethylsiloxane (PDMS) analysis and detection. Experimental parameters were refined while performing a full factorial experimental design (FFD) for the screening, extended to a face centered central composite design (FCCD) for the optimisation. Analyses were led on standard PDMS reference material for the optimisation. Two-way ANOVA statistics and surface responses were used to define the most adequate parameters for the analysis. The adequate parameters were then applied to five condom extracts that were analysed in replicates. Chemometrics was used to evaluate within and between sample variations. Separation of the samples was investigated and was not found to be applicable to the limited set of samples. Issues in reproducibility were highlighted and further investigation on different instruments are necessary to improve the reported study.

中文翻译：

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用于硅基润滑剂分析的 Py-GC/MS 方法的优化

摘要 安全套证据可以使用多种分析技术进行分析，例如 FTIR、MALDI-MS 或 DART-TOF-MS，但唯一一种用于真实样本以在性侵犯或强奸案的背景下进行转移和持久性研究的方法是Py-GC/MS。然而，还没有研究确定哪些特定的热解参数最适合分析硅基润滑剂，尤其是在分析的可重复性方面。本研究着眼于不同报告的热解参数，目的是优化聚二甲基硅氧烷 (PDMS) 分析和检测的这些参数。在为筛选执行全因子实验设计 (FFD) 时，对实验参数进行了细化，并扩展到以面为中心的中心复合设计 (FCCD) 进行优化。对标准 PDMS 参考材料进行分析以进行优化。双向方差分析统计和表面响应用于定义最适合分析的参数。然后将适当的参数应用于重复分析的五种避孕套提取物。化学计量学用于评估样品变化之内和之间。对样品的分离进行了研究，发现它不适用于有限的样品组。强调了可重复性问题，需要对不同仪器进行进一步调查，以改进报告的研究。然后将适当的参数应用于重复分析的五种避孕套提取物。化学计量学用于评估样品变化之内和之间。对样品的分离进行了研究，发现它不适用于有限的样品组。强调了可重复性问题，需要对不同仪器进行进一步调查，以改进报告的研究。然后将适当的参数应用于重复分析的五种避孕套提取物。化学计量学用于评估样品变化之内和之间。对样品的分离进行了研究，发现它不适用于有限的样品组。强调了可重复性问题，需要对不同仪器进行进一步调查，以改进报告的研究。