Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.
Department of Clinical Pharmacology, Karolinska University Laboratory, Stockholm, Sweden.
Drug Test Anal. 2022 Feb;14(2):371-376. doi: 10.1002/dta.3190. Epub 2021 Nov 10.
During routine urine drug testing for cannabis use targeting delta-9-tetrahydrocannabinol carboxylic acid (delta-9-THC-COOH) at the Karolinska University Laboratory in Sweden, an unknown interfering peak was observed in the liquid-chromatographic-tandem mass-spectrometric (LC-MS/MS) confirmative analysis. The peak showed the same exact mass and most abundant fragments as delta-9-THC-COOH but a slightly shorter retention time, thereby not fulfilling all requirements for a positive identification. The analytical results suggested that it was a similar compound, and with access to reference material, it could be identified as the double bond isomer delta-8-THC-COOH. Delta-8-THC has recently become popular as a recreational drug, although its legality varies and is sometimes unclear. In Sweden, all THC isomers are classified substances. The slight difference in retention times was sufficient to distinguish the THC-COOH isomers in the routine LC-MS/MS method, but another LC method allowed better peak separation and individual quantification. At the Karolinska University Laboratory, delta-8-THC-COOH was first observed in April 2020, and the highest incidence was noted in June 2020 when it was present in 5.3% of all THC-COOH-positive samples. The incidence later decreased to today only occasional findings. Large differences in the relative presence of the isomers in the urine samples indicated different origin, for example, synthetically produced pure delta-8-THC, or mixtures of both THC isomers formed during combustion of cannabidiol (CBD). In conclusion, the appearance of delta-8-THC and other isomers on the recreational drug market risks causing analytical and medico-legal problems, due to confusion with delta-9-THC.
在瑞典卡罗林斯卡大学实验室进行的常规尿液药物检测中，针对大麻中 δ-9-四氢大麻酸羧酸（δ-9-THC-COOH）进行液相色谱-串联质谱（LC-MS/MS）确证分析时，观察到一个未知的干扰峰。该峰具有与 δ-9-THC-COOH 相同的精确质量和最丰富的碎片，但保留时间略短，因此不符合阳性鉴定的所有要求。分析结果表明，它是一种类似的化合物，并且在有参考物质的情况下，可以将其鉴定为双键异构体 δ-8-THC-COOH。δ-8-THC 最近作为一种消遣性药物变得流行，尽管其合法性各不相同，有时也不清楚。在瑞典，所有的 THC 异构体都被归类为管制物质。保留时间的微小差异足以在常规 LC-MS/MS 方法中区分 THC-COOH 异构体，但另一种 LC 方法可以实现更好的峰分离和单独定量。在卡罗林斯卡大学实验室，δ-8-THC-COOH 于 2020 年 4 月首次被观察到，2020 年 6 月的检出率最高，当时在所有 THC-COOH 阳性样本中检出率为 5.3%。此后，检出率下降到如今只是偶尔发现。尿液样本中异构体的相对存在存在较大差异，表明来源不同，例如，合成生产的纯 δ-8-THC，或燃烧大麻二酚（CBD）过程中形成的两种 THC 异构体的混合物。总之，δ-8-THC 和其他异构体出现在消遣性药物市场上，可能会因与 δ-9-THC 混淆而导致分析和法医学问题。
