In forensic toxicology, high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) is increasingly used for the fast and sensitive measurement of a wide range of drugs. For our routine casework, a liquid chromatography atmospheric pressure chemical ionization-tandem mass spectrometry (LC-APCI-MS/MS) method for the quantification of Δ9-tetrahydrocannabinol (Δ9-THC), cannabinol (CBN) and cannabidiol (CBD) in hair was established and fully validated. Separation was achieved using a Kinetex® C18 column (100 mm × 2.1 mm, 100 Å, 1.7 μm, Phenomenex) at a flow rate of 0.5 mL/min. Measurements were performed on a QTrap 5,500 mass spectrometer (Sciex, Darmstadt, Germany). Unexpected signals were observed in authentic THC-positive hair samples. First, a signal with a slightly shifted retention time of THC whose origin could be assigned to the isomer Δ8-THC. Second, additional peaks exhibiting the same fragments as CBN and Δ9-THC but eluting at different retention times were detected. Spiking experiments and enhanced product ion scans (EPI) pointed to the origin of these additional signals as result of in-source decarboxylation of Δ9-tetrahydrocannabinolic acid A (Δ9-THCA-A) into Δ9-THC and further partial oxidation of Δ9-THC into CBN, respectively. Positive findings of Δ9-THCA-A in hair have been shown to derive from external contamination, therefore, the herein described artefacts may be used as indirect markers for external contamination.

中文翻译：

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头发中 Δ9-THC、CBN 和 CBD 的 LC-MS/MS 分析：人工制品调查

在法医毒理学中，高效液相色谱串联质谱 (LC-MS/MS) 越来越多地用于对各种药物进行快速和灵敏的测量。对于我们的常规案例，液相色谱常压化学电离串联质谱 (LC-APCI-MS/MS) 方法用于定量头发中的 Δ9-四氢大麻酚 (Δ9-THC)、大麻酚 (CBN) 和大麻二酚 (CBD)成立并得到充分验证。使用 Kinetex® C18 色谱柱（100 mm × 2.1 mm，100 Å，1.7 μm，Phenomenex）以 0.5 mL/min 的流速实现分离。在 QTrap 5,500 质谱仪（Sciex，Darmstadt，Germany）上进行测量。在真实的 THC 阳性头发样本中观察到了意外的信号。第一的，THC 的保留时间略有偏移的信号，其起源可归于异构体 Δ8-THC。其次，检测到与 CBN 和 Δ9-THC 具有相同片段但在不同保留时间洗脱的其他峰。尖峰实验和增强的产物离子扫描 (EPI) 指出这些附加信号的起源是 Δ9-四氢大麻酚 A (Δ9-THCA-A) 源内脱羧成 Δ9-THC 和进一步部分氧化 Δ9-THC分别进入 CBN。头发中 Δ9-THCA-A 的阳性发现已被证明源自外部污染，因此，本文所述的人工制品可用作外部污染的间接标志物。尖峰实验和增强的产物离子扫描 (EPI) 指出这些附加信号的起源是 Δ9-四氢大麻酚 A (Δ9-THCA-A) 源内脱羧成 Δ9-THC 和进一步部分氧化 Δ9-THC分别进入 CBN。头发中 Δ9-THCA-A 的阳性发现已被证明源自外部污染，因此，本文所述的人工制品可用作外部污染的间接标志物。尖峰实验和增强的产物离子扫描 (EPI) 指出这些附加信号的起源是 Δ9-四氢大麻酚 A (Δ9-THCA-A) 源内脱羧成 Δ9-THC 和进一步部分氧化 Δ9-THC分别进入 CBN。头发中 Δ9-THCA-A 的阳性发现已被证明源自外部污染，因此，本文所述的人工制品可用作外部污染的间接标志物。