Capistran Briana A, Sisco Edward
National Institute of Standards and Technology, Gaithersburg, MD, USA.
Forensic Chem. 2022 Sep;30. doi: 10.1016/j.forc.2022.100435.
Techniques developed for the screening of forensic samples can be useful for increasing sample throughput and decreasing backlog in forensic laboratories. One such technique, rapid gas chromatography mass spectrometry (GC-MS), allows for fast sample screening (≈1 min) and has gained interest in recent years for forensic applications. This work focuses on the development of a method for ignitable liquid analysis using rapid GC-MS. A sampling protocol and temperature program were developed for the analysis of these volatile samples. Using the optimized method for analysis, the limits of detection for compounds commonly found in ignitable liquids ranged from 0.012 mg/mL to 0.018 mg/mL. Once the method was developed, neat ignitable liquids (, gasoline and diesel fuel) were analyzed, and major components in each liquid were identified. The identification of major compounds in gasoline and diesel fuel in the presence of substrate interferences was then assessed through the analysis of simulated fire debris samples. Three different substrates were spiked with each ignitable liquid, burned, and analyzed. Major compounds in both liquids were identified using the total ion chromatograms, relevant extracted ion profiles, and deconvolution methods.
为法医样本筛查开发的技术可用于提高法医实验室的样本通量并减少积压。快速气相色谱 - 质谱联用(GC - MS)就是这样一种技术,它能实现快速样本筛查(约1分钟),近年来在法医应用中受到关注。这项工作聚焦于开发一种使用快速GC - MS进行可燃液体分析的方法。针对这些挥发性样本的分析,制定了采样方案和温度程序。采用优化后的分析方法,可燃液体中常见化合物的检测限在0.012 mg/mL至0.018 mg/mL之间。方法开发完成后,对纯可燃液体(如汽油和柴油)进行了分析,并鉴定了每种液体中的主要成分。然后通过分析模拟火灾残骸样本,评估在存在基质干扰的情况下汽油和柴油中主要化合物的鉴定情况。将每种可燃液体添加到三种不同的基质中,燃烧后进行分析。利用总离子色谱图、相关提取离子图谱和去卷积方法鉴定了两种液体中的主要化合物。