Department of Chemistry, Western Illinois University, Macomb, IL 61455, USA.
Department of Chemistry, Western Illinois University, Macomb, IL 61455, USA.
J Pharm Biomed Anal. 2024 Jan 20;238:115847. doi: 10.1016/j.jpba.2023.115847. Epub 2023 Nov 7.
A LC-ESI/MS/MS method was developed for quantification of up to eighteen cannabinoids, the maximum number published so far. A thorough study of published LC-ESI/MS/MS methods using triple quadrupole mass spectrometers revealed a possible misconception that multiple reaction monitoring (MRM) was able to definitively differentiate structural isomers of cannabinoids, especially Δ-/Δ-tetrahydrocannabinol (THC), which explained why many of those methods were developed for a limited number of cannabinoids, as small as two, and did not include Δ-THC. In this study, the use of a quadrupole time-of-flight (QTOF) mass spectrometer for targeted analysis indicated that MRM could not definitively distinguish structural isomers of Δ-THC, with a possible exception of cannabicyclol (CBL) for less accurate quantification, so their baseline separation was essential for their accurate quantification. After the developed method was successfully validated according to the ISO 17025 guidelines, it was further applied for the analysis of eighteen hemp-derived products, including drinks, water-soluble oils, topical serum, body lotion, face cream, lip balm, gummies, hard candy, coffee, snacks, and pet treats. The LOQ was 0.00008% (w/w) for drinks with the analysis of 12.5 mg/mL extracts, while the LOQ was 0.008% (w/w) for other samples because 125 μg/mL extracts were analyzed due to higher content of cannabinoids in non-drink samples. For the first-time, extraction recovery and matrix effect were tracked in real-time for each sample being analyzed, obtaining 92.9-106.3% and 91.3-120.2% in triplicate measurements, respectively, by spiking abnormal cannabidiol (ACBD), a cannabinoid not naturally present in hemp, into each sample before extraction and ACBD-d into each sample after extraction.
建立了一种 LC-ESI/MS/MS 方法，用于定量分析多达十八种大麻素，这是迄今为止发表的最多数量。对使用三重四极杆质谱仪的已发表 LC-ESI/MS/MS 方法进行了深入研究，揭示了一种可能的误解，即多重反应监测 (MRM) 能够明确区分大麻素的结构异构体，特别是 Δ-/Δ-四氢大麻酚 (THC)，这解释了为什么许多方法仅适用于有限数量的大麻素，例如两种，并且不包括 Δ-THC。在这项研究中，使用四极杆飞行时间 (QTOF) 质谱仪进行靶向分析表明，MRM 不能明确区分 Δ-THC 的结构异构体，可能除了大麻环萜酚 (CBL) 外，其定量不太准确，因此它们的基线分离对于它们的准确定量至关重要。根据 ISO 17025 指南成功验证开发方法后，进一步将其应用于分析十八种大麻素衍生产品，包括饮料、水溶性油、局部血清、身体乳液、面霜、润唇膏、 gummies、硬糖、咖啡、零食和宠物零食。对于饮料，LOQ 为 0.00008%（w/w），分析浓度为 12.5 mg/mL 提取物；对于其他样品，LOQ 为 0.008%（w/w），因为分析浓度为 125 μg/mL 提取物，因为非饮料样品中的大麻素含量较高。首次在实时跟踪每个被分析样品的提取回收率和基质效应，通过在提取前向每个样品中添加异常大麻二酚 (ACBD)（一种大麻素中不存在的大麻素）和提取后向每个样品中添加 ACBD-d，分别获得 92.9-106.3%和 91.3-120.2%的三重复测量值。
