National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa, Chiba 277-0882, Japan.
Anal Bioanal Chem. 2012 Jan;402(3):1257-67. doi: 10.1007/s00216-011-5576-0. Epub 2011 Dec 7.
Rapid and precise identification of toxic substances is necessary for urgent diagnosis and treatment of poisoning cases and for establishing the cause of death in postmortem examinations. However, identification of compounds in biological samples using gas chromatography and liquid chromatography coupled with mass spectrometry entails time-consuming and labor-intensive sample preparations. In this study, we examined a simple preparation and highly sensitive analysis of drugs in biological samples such as urine, plasma, and organs using thin-layer chromatography coupled with matrix-assisted laser desorption/ionization mass spectrometry (TLC/MALDI/MS). When the urine containing 3,4-methylenedioxymethamphetamine (MDMA) without sample dilution was spotted on a thin-layer chromatography (TLC) plate and was analyzed by TLC/MALDI/MS, the detection limit of the MDMA spot was 0.05 ng/spot. The value was the same as that in aqueous solution spotted on a stainless steel plate. All the 11 psychotropic compounds tested (MDMA, 4-hydroxy-3-methoxymethamphetamine, 3,4-methylenedioxyamphetamine, methamphetamine, p-hydroxymethamphetamine, amphetamine, ketamine, caffeine, chlorpromazine, triazolam, and morphine) on a TLC plate were detected at levels of 0.05-5 ng, and the type (layer thickness and fluorescence) of TLC plate did not affect detection sensitivity. In addition, when rat liver homogenate obtained after MDMA administration (10 mg/kg) was spotted on a TLC plate, MDMA and its main metabolites were identified using TLC/MALDI/MS, and the spots on a TLC plate were visualized by MALDI/imaging MS. The total analytical time from spotting of intact biological samples to the output of analytical results was within 30 min. TLC/MALDI/MS enabled rapid, simple, and highly sensitive analysis of drugs from intact biological samples and crude extracts. Accordingly, this method could be applied to rapid drug screening and precise identification of toxic substances in poisoning cases and postmortem examinations.
快速准确地鉴定有毒物质对于中毒病例的紧急诊断和治疗以及尸检中确定死因是必要的。然而，使用气相色谱和液相色谱与质谱联用对生物样品中的化合物进行鉴定需要耗时且劳动密集型的样品制备。在这项研究中，我们使用薄层色谱与基质辅助激光解吸/电离质谱联用（TLC/MALDI/MS）检查了尿液、血浆和器官等生物样品中药物的简单制备和高灵敏度分析。当未稀释的含有 3,4-亚甲二氧基甲基苯丙胺（MDMA）的尿液点样于薄层色谱（TLC）板上并通过 TLC/MALDI/MS 分析时，MDMA 斑点的检测限为 0.05 ng/斑点。该值与点样于不锈钢板上的水溶液相同。在 TLC 板上测试的所有 11 种精神药物（MDMA、4-羟基-3-甲氧基苯丙胺、3,4-亚甲二氧基苯丙胺、甲基苯丙胺、对羟甲基苯丙胺、苯丙胺、氯胺酮、咖啡因、氯丙嗪、三唑仑和吗啡）均以 0.05-5 ng 的水平检测到，并且 TLC 板的类型（层厚和荧光）不会影响检测灵敏度。此外，当给予 MDMA 后（10 mg/kg）的大鼠肝匀浆点样于 TLC 板上时，使用 TLC/MALDI/MS 鉴定了 MDMA 及其主要代谢物，并用 MALDI/成像 MS 可视化 TLC 板上的斑点。从完整生物样品点样到输出分析结果的总分析时间在 30 分钟内。TLC/MALDI/MS 能够快速、简单、高灵敏度地分析完整生物样品和粗提取物中的药物。因此，该方法可应用于中毒病例和尸检中快速药物筛选和有毒物质的精确鉴定。
