Poison Control and Forensic Chemistry Center, Ministry of Health, Medina, Saudi Arabia.
King Abdul-Aziz Hospital, Ministry of Health, Jeddah, Saudi Arabia.
Drug Test Anal. 2021 Jun;13(6):1095-1107. doi: 10.1002/dta.3005. Epub 2021 Feb 16.
The aim of this work was to develop and validate a liquid chromatography-tandem mass spectrometry method for detecting of the main cannabinoids, cannabinol (CBN) and tetrahydrocannabinol (THC) and the primary metabolite 11-nor-9-carboxy-Δ -tetrahydrocannabinol (THC-COOH) in hair samples. Extraction of the cannabinoids was carried out by a polymeric strong anion mixed-mode solid-phase extraction cartridge and then employing methanolic HCl followed by 2-fluoro-1-methylpyridinium-p-toluenesulfonate (FMP-TS) as a derivatization procedure of carboxyl and phenolic groups, respectively, offering enhanced sensitivity for the detection of THC-COOH in hair matrices. Formation of a methyl ester increased its lipophilicity and removed the negative charge on the carboxyl group. Calibration curves were prepared over the range of 0.02-4 pg/mg of hair for THC and CBN and 0.2-12 pg/mg of hair for THC-COOH. The extraction recovery was between 81% and 105% for all compounds. The limit of detection (LOD) and limit of quantification (LOQ) were 2 and 20 pg/mg, respectively, for both CBN and THC and 0.1 and 0.2 pg/mg, respectively, for THC-COOH, which met the society of hair testing recommendation. Intra-assay and interassay precision were always lower than 4% and 11%, respectively for these cannabinoids, whereas intra-assay and interassay bias were between +14% and -18% and +15% and -12%, respectively. Twenty-seven hair specimens from cannabis users were investigated. The concentrations of CBN, THC and THC-COOH gave ranges of (0.022-2.562 ng/mg), (0.049-0.431 ng/mg) and (0.222-4.867 pg/mg), respectively. This new method of derivatization improves the LOD to ensure detection of the metabolite.
本工作旨在建立并验证一种液相色谱-串联质谱法，用于检测头发样本中主要大麻素大麻酚（CBN）和四氢大麻酚（THC）及其初级代谢物 11-去羧基-Δ9-四氢大麻酸（THC-COOH）。采用聚合型强阴离子混合模式固相萃取小柱提取大麻素，然后使用甲醇盐酸和 2-氟-1-甲基吡啶𬭩对甲苯磺酸盐（FMP-TS）分别对羧基和酚基进行衍生化处理，分别提高了检测头发基质中 THC-COOH 的灵敏度。甲酯的形成增加了其亲脂性并消除了羧基上的负电荷。校准曲线在 THC 和 CBN 的 0.02-4 pg/mg 和 THC-COOH 的 0.2-12 pg/mg 范围内制备。所有化合物的提取回收率在 81%至 105%之间。CBN 和 THC 的检测限（LOD）和定量限（LOQ）分别为 2 和 20 pg/mg，THC-COOH 的检测限（LOD）和定量限（LOQ）分别为 0.1 和 0.2 pg/mg，均符合头发检测协会的建议。对于这些大麻素，内标和日间精密度始终低于 4%和 11%，而内标和日间偏差分别为+14%至-18%和+15%至-12%。对 27 份大麻使用者的头发样本进行了研究。CBN、THC 和 THC-COOH 的浓度范围分别为（0.022-2.562 ng/mg）、（0.049-0.431 ng/mg）和（0.222-4.867 pg/mg）。这种新的衍生化方法提高了 LOD，确保了代谢物的检测。
