Quantitation of Δ8-THC, Δ9-THC, Cannabidiol and 10 Other Cannabinoids and Metabolites in Oral Fluid by HPLC-MS-MS

Quantitative analysis of Delta(9)-tetrahydrocannabinol (Delta(9)-THC) in oral fluid has gained increasing interest in clinical and forensic toxicology laboratories. New medicinal and/or recreational cannabinoid products require laboratories to distinguish different patterns of cannabinoid use. This study validated a high-performance liquid chromatography-tandem mass spectrometry method for 13 different cannabinoids, including (-)-trans-Delta(8)-tetrahydrocannabinol (Delta(8)-THC), (-)-trans-Delta(9)-tetrahydrocannabinol (Delta(9)-THC), cannabidiol (CBD), Delta(9)-tetrahydrocannabinolic acid-A (Delta(9)-THCA-A), cannabidiolic acid (CBDA), 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-Delta(9)-THC), 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (Delta(9)-THCCOOH), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabidiorcol (CBD-C1), cannabichromene (CBC), cannabinol (CBN) and cannabigerol (CBG), in oral fluid. Baseline separation was achieved in the entire quantitation range between Delta(9)-THC and its isomer Delta(8)-THC. The quantitation range of Delta(9)-THC, Delta(8)-THC and CBD was from 0.1 to 800 ng/mL. Two hundred human subject oral fluid samples were analyzed with this method after solid phase extraction. Among the 200 human subject oral fluid samples, all 13 cannabinoid analytes were confirmed in at least one sample. Delta(8)-THC was confirmed in 11 samples, with or without the presence of Delta(9)-THC. A high concentration of 11-OH-Delta(9)-THC or Delta(9)-THCCOOH (>400 ng/mL) was confirmed in three samples. CBD, Delta(9)-THCA-A, THCV, CBN and CBG were confirmed in 74, 39, 44, 107 and 112 of the 179 confirmed Delta(9)-THC-positive samples, respectively. The quantitation of multiple cannabinoids and metabolites in oral fluid simultaneously provides valuable information for revealing cannabinoid consumption and interpreting cannabinoid-induced driving impairment.