Office of the Chief Medical Examiner, Forensic Laboratory Division, San Francisco, CA, USA.
Department of Laboratory Medicine, University of California, San Francisco, CA, USA.
J Anal Toxicol. 2020 Apr 2;44(5):422-439. doi: 10.1093/jat/bkaa003.
Systematic toxicological approaches that employ both ideology changes and improvements in instrumentation and sample extraction allow for improved toxicology testing efficiency through lower sensitivities, higher specificity and minimized resource use. Historically, the San Francisco Office of the Chief Medical Examiner relied heavily on a gas chromatography mass spectrometry (GC-MS) testing regime, comprised of individual drug-class confirmation and quantitation assays. Traditional methods utilizing GC-MS typically require iterations of testing, exhausting sample volume, and hindering productivity and turnaround times, particularly for polypharmacy cases frequently seen in modern postmortem toxicology. The method described here consolidated the scope of seven legacy methods into a single liquid chromatography tandem mass spectrometry (LC-MS/MS) method for better sensitivity, higher throughput, minimal sample consumption for the quantitation of drugs of abuse and improved quality assurance with the incorporation of smart, automated processing. About 100 μL of blood or urine were rapidly extracted using a simple acetonitrile protein crash and subsequent in-vial filtration and injected on to an LC-MS-MS system. The developed method was fully validated to SWGTOX and international guidelines and incorporated 55 analytes along with a customized query that facilitates rapid and consistent application of acceptability criteria for data processing and review. Applicability was demonstrated with the analysis of 1,389 samples (858 blood and 531 urine) where at least 41% of positive results may have been missed due to their decreased sensitivity and 11% of results were not within the scope of the previous analytical methods estimated. On average, cases in this study would have previously required three distinct GC-MS assays, 3 mL of blood, and upwards of 30 h of active staff time. The described LC-MS-MS analytical approach has mitigated the need to perform multiple assays, utilized only 0.1 mL of sample, significantly reduced analyst work time, incorporated 10 additional analytes and allowed for a more comprehensive testing regime to better inform cause of death determinations.
系统毒理学方法既改变了理念，又改进了仪器和样品提取，从而通过降低灵敏度、提高特异性和最小化资源利用，提高毒理学测试效率。历史上，旧金山首席法医办公室严重依赖气相色谱质谱（GC-MS）测试方案，包括个别药物类别的确认和定量分析。传统的 GC-MS 方法通常需要迭代测试，消耗大量样本量，阻碍生产力和周转时间，特别是在现代法医毒理学中经常遇到的多药情况。这里描述的方法将七个传统方法的范围整合到一个单一的液相色谱串联质谱（LC-MS/MS）方法中，以提高灵敏度、更高的通量、最小的样本消耗，用于定量滥用药物，并通过智能、自动化处理提高质量保证。大约 100 μL 的血液或尿液通过简单的乙腈蛋白沉淀和随后的管内过滤进行快速提取，并注入 LC-MS-MS 系统。该方法经过全面验证，符合 SWGTOX 和国际指南，并纳入了 55 种分析物，以及一个定制的查询，便于快速一致地应用数据处理和审查的可接受标准。通过对 1389 个样本（858 个血液和 531 个尿液）的分析证明了适用性，其中至少 41%的阳性结果可能由于灵敏度降低而被遗漏，11%的结果不在以前分析方法的范围内。平均而言，本研究中的病例以前需要进行三次不同的 GC-MS 检测，3 毫升血液，以及 30 小时以上的活跃员工时间。所描述的 LC-MS-MS 分析方法减少了对多次检测的需求，仅使用 0.1 毫升的样本，大大减少了分析员的工作时间，纳入了 10 种额外的分析物，并允许进行更全面的检测方案，以更好地告知死因确定。
