Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, United States.
J Appl Lab Med. 2023 Jul 5;8(4):665-673. doi: 10.1093/jalm/jfad017.
Delta-8 tetrahydrocannabinol (Δ8-THC) is a naturally occurring or synthetically prepared cannabinoid that elicits psychological and physiological experiences commonly reported for its more infamous isomer, delta-9 tetrahydrocannabinol (Δ9-THC). Unlike Δ9-THC, Δ8-THC products are generally legal under federal law and there has been a rise in their usage. One of the main targets for detection and quantitation of Δ9-THC is its inactive metabolite, 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (Δ9-THC-COOH).
This study evaluated the ability of the currently used Δ9-THC-COOH immunoassay and gas chromatography-mass spectrometry (GC-MS) methods to detect 11-nor-9-carboxy-Δ8-tetrahydrocannabinol (Δ8-THC-COOH) and distinguish it from Δ9-THC-COOH.
The EMIT II Plus® Cannabinoid immunoassay for Δ9-THC-COOH with a cutoff of 20 ng/mL showed positive results for Δ8-THC-COOH with concentrations of 30 ng/mL or higher. Although many of the ion fragments generated by mass spectrometry were found to overlap between the 2 compounds, the GC-MS method presently used to quantify Δ9-THC-COOH separated the 2 compounds sufficiently to identify them independently by relative retention time.
Current immunoassays and GC-MS methods should be evaluated for the ability to detect and distinguish the presence of Δ8-THC-COOH.
Delta-8 四氢大麻酚（Δ8-THC）是一种天然存在或合成制备的大麻素，它引起的心理和生理体验通常与其更臭名昭著的异构体 delta-9 四氢大麻酚（Δ9-THC）报告的相似。与 Δ9-THC 不同，Δ8-THC 产品在联邦法律下通常是合法的，而且它们的使用量有所增加。检测和定量 Δ9-THC 的主要目标之一是其无活性代谢物 11-去甲-9-羧基-Δ9-四氢大麻酚（Δ9-THC-COOH）。
本研究评估了目前用于检测 11-去甲-9-羧基-Δ8-四氢大麻酚（Δ8-THC-COOH）并将其与 Δ9-THC-COOH 区分开来的 Δ9-THC-COOH 免疫分析和气相色谱-质谱（GC-MS）方法的能力。
EMIT II Plus®大麻素免疫分析检测 Δ9-THC-COOH 的截止值为 20 ng/mL，对浓度为 30 ng/mL 或更高的 Δ8-THC-COOH 显示阳性结果。尽管质谱产生的许多离子碎片在这两种化合物之间被发现重叠，但目前用于定量 Δ9-THC-COOH 的 GC-MS 方法足以通过相对保留时间将这两种化合物分开，从而独立识别它们。
当前的免疫分析和 GC-MS 方法应评估其检测和区分 Δ8-THC-COOH 存在的能力。
