Analysis of ignitable liquids in fire debris samples can be a time-consuming process, from extraction of volatile compounds to instrumental analysis. Rapid gas chromatography-mass spectrometry (GC–MS) is a screening technique that can be utilized prior to confirmatory GC–MS analysis to provide an informative screening approach and possibly reduce the need to further analyze negative samples. Though rapid GC–MS is fast (less than two minutes), extraction techniques such as passive headspace extraction remain a bottleneck for decreasing overall workflow times. In this work, solid phase microextraction (SPME) was implemented with rapid GC–MS for ignitable liquid analysis for a faster, more sensitive screening approach compared to extraction with passive headspace. Using optimized inlet conditions, limits of detection as low as 27 ng/mL per compound were achieved. Gasoline and diesel fuel were extracted and analyzed, and major compounds in each liquid were identified in the resulting chromatograms. Extracted ion profiles (EIPs) and deconvolution methods were useful for additional compound identifications. Lastly, the SPME-rapid GC–MS workflow was extended to the analysis of gasoline and diesel fuel in mock burn samples using carpet and wood substrates. From SPME sample extraction to rapid GC–MS instrumental analysis and data processing, the total workflow for a single sample was reduced to under 20 min. These results indicate that SPME is a suitable injection technique for rapid GC–MS to provide a fast and sensitive screening approach for fire debris applications.

中文翻译：

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实施 SPME 和快速 GC-MS 作为法医火灾碎片应用的筛查方法

从挥发性化合物的提取到仪器分析，火残骸样品中可燃液体的分析可能是一个耗时的过程。快速气相色谱-质谱 (GC-MS) 是一种筛选技术，可在验证性 GC-MS 分析之前使用，以提供信息丰富的筛选方法，并可能减少进一步分析阴性样品的需要。尽管快速 GC-MS 速度很快（不到两分钟），但被动顶空萃取等萃取技术仍然是缩短整体工作流程时间的瓶颈。在这项工作中，固相微萃取 (SPME) 与快速 GC-MS 一起用于可燃液体分析，与被动顶空萃取相比，可实现更快、更灵敏的筛选方法。使用优化的进样口条件，每种化合物的检测限可低至 27 ng/mL。提取并分析汽油和柴油，并在所得色谱图中鉴定出每种液体中的主要化合物。提取离子谱 (EIP) 和反卷积方法对于其他化合物鉴定非常有用。最后，SPME-快速 GC-MS 工作流程扩展到使用地毯和木材基材分析模拟燃烧样品中的汽油和柴油燃料。从 SPME 样品提取到快速 GC-MS 仪器分析和数据处理，单个样品的总工作流程缩短至 20 分钟以下。这些结果表明 SPME 是一种适合快速 GC-MS 的进样技术，可为火灾碎片应用提供快速、灵敏的筛选方法。