Houston Forensic Science Center, 500 Jefferson Street, 13th Floor, Houston, TX 77002, USA.
Division of Forensic Toxicology, Armed Forces Medical Examiner System, 115 Purple Heart Drive, Dover AFB, Dover, DE 19902, USA.
J Anal Toxicol. 2022 Apr 21;46(4):343-349. doi: 10.1093/jat/bkac007.
Among the abundance of cannabinoids identified in cannabis, the active parent drug, Δ9-tetrahydrocannabinol (Δ9-THC), and its oxidized metabolite, 11-nor-9-carboxy-Δ9-THC (Δ9-THCCOOH), are attractive analytical targets to detect cannabis use. More recently, confirmation of these analytes may be hindered by a related interfering compound. Forensic toxicology laboratories attribute this phenomenon to an increase in cases containing Δ8-tetrahydrocannabinol (Δ8-THC) and 11-nor-9-carboxy-Δ8-THC (Δ8-THCCOOH). It is technically challenging to chromatographically resolve and accurately quantify Δ8- and Δ9-THC and THCCOOH in toxicology specimens due to their structural resemblance. This study describes a validated method to resolve and quantify active Δ8-THC and Δ9-THC in blood while qualitatively confirming the inactive metabolites Δ8-THCCOOH and Δ9-THCCOOH in blood and urine. Analytes are extracted and concentrated by solid-phase extraction and analyzed by liquid chromatography--electrospray ionization tandem mass spectrometry, which is amenable to modern toxicology laboratory routine workflows. This procedure offers a clear solution to untangling mixtures of these isomers, particularly in cases where Δ8-THC and its metabolite are the sole or dominant form.
在大麻中鉴定出的大量大麻素中，活性母体药物 Δ9-四氢大麻酚（Δ9-THC）及其氧化代谢物 11-去甲-9-羧基-Δ9-THC（Δ9-THCCOOH）是检测大麻使用的有吸引力的分析目标。最近，这些分析物的确认可能会受到相关干扰化合物的阻碍。法医毒理学实验室将这种现象归因于含有 Δ8-四氢大麻酚（Δ8-THC）和 11-去甲-9-羧基-Δ8-THC（Δ8-THCCOOH）的案例增加。由于它们的结构相似，在毒理学样本中色谱分离和准确定量 Δ8-和 Δ9-THC 和 THCCOOH 具有技术挑战性。本研究描述了一种经过验证的方法，可在血液中分离和定量活性 Δ8-THC 和 Δ9-THC，同时定性确认血液和尿液中无活性代谢物 Δ8-THCCOOH 和 Δ9-THCCOOH。分析物通过固相萃取提取和浓缩，并通过液相色谱-电喷雾串联质谱分析，适用于现代毒理学实验室常规工作流程。该程序为解决这些异构体混合物提供了明确的解决方案，特别是在 Δ8-THC 及其代谢物是唯一或主要形式的情况下。
