Forensic Toxicology Laboratory, National Toxicology Center, Albany, NY, USA.
Department of Pathology and Laboratory Medicine, Albany Medical College, Albany, NY, USA.
J Anal Toxicol. 2023 Nov 1;47(8):709-718. doi: 10.1093/jat/bkad048.
Confirmation of cannabinoid use by forensic toxicology testing in urine has been traditionally focused on ∆9-tetrahydrocannabinol (∆9-THC) with analysis of its major metabolite, 11-nor-9-carboxy-∆9-THC (∆9-cTHC), in free and conjugated forms. Legalization of hemp, however, has led to the widespread production and sale of cannabidiol (CBD) derivatives with psycho-activity, including ∆8-THC and ∆10-THC isomers. The increasing availability and growing use of isomer derivatives necessitate an expanded scope of cannabinoid confirmation test protocols. We report a quantitative, isomer-selective method of cannabinoid confirmation by liquid chromatography-tandem mass spectrometry determination of parent drug isomers (∆8-THC, ∆9-THC, ∆10-THC and CBD) as well as isomeric metabolites (∆8-cTHC and ∆9-cTHC). An efficient C18 phase chromatography on 1.6-µm solid core particles was used with a step gradient for near isocratic separation of both early-eluting THC metabolite isomers and later-eluting CBD and THC isomers. A rapid method of hydrolysis, dilution and analysis was employed for the quantitative co-determination of free and conjugated analytes, using stable isotope internal standardization. Method validation is reported, along with interference assessment from a prior confirmation method. Casework experience with the isomer-selective method revealed a 14% prevalence of ∆8-cTHC positive cases with a pattern of concomitant ∆8-THC and ∆9-THC use. A comparison of ∆8-cTHC and ∆9-cTHC phase two metabolism is also reported.
传统上，法医毒理学检测尿液中的大麻素使用情况主要集中在 ∆9-四氢大麻酚（∆9-THC）上，分析其主要代谢物 11-去甲-9-羧基-∆9-THC（∆9-cTHC）的游离和结合形式。然而，大麻合法化导致具有精神活性的大麻二酚（CBD）衍生物，包括 ∆8-THC 和 ∆10-THC 异构体，广泛生产和销售。异构体衍生物的可用性增加和使用增加需要扩大大麻素确认测试方案的范围。我们报告了一种通过液相色谱-串联质谱法测定母体药物异构体（∆8-THC、∆9-THC、∆10-THC 和 CBD）以及异构体代谢物（∆8-cTHC 和 ∆9-cTHC）的定量、异构体选择性大麻素确认方法。使用 1.6-µm 实心核粒子进行高效 C18 相色谱分离，采用分步梯度实现早期洗脱 THC 代谢物异构体和晚期洗脱 CBD 和 THC 异构体的近乎等度分离。采用快速水解、稀释和分析方法，使用稳定同位素内标法对游离和结合分析物进行定量共测定。报告了方法验证情况，并评估了先前确认方法的干扰情况。异构体选择性方法的案例经验显示，∆8-cTHC 阳性病例的患病率为 14%，同时伴有 ∆8-THC 和 ∆9-THC 的使用。还报告了 ∆8-cTHC 和 ∆9-cTHC 第二阶段代谢的比较。
