Quantitative Determination of 9 -THC, CBG, CBD, Their Acid Precursors and Five Other Neutral Cannabinoids by UHPLC-UV-MS

Cannabinoids are a group of terpenophenolic compounds in the medicinal plant Cannabis sativa (Cannabaceae family). Cannabigerolic acid, (9) -tetrahydrocannabinolic acid A, cannabidiolic acid, (9) -tetrahydrocannabinol, cannabigerol, cannabidiol, cannabichromene, and tetrahydrocannabivarin are major metabolites in the classification of different strains of C. sativa . Degradation or artifact cannabinoids cannabinol, cannabicyclol, and (8) -tetrahydrocannabinol are formed under the influence of heat and light during processing and storage of the plant sample. An ultrahigh-performance liquid chromatographic method coupled with photodiode array and single quadruple mass spectrometry detectors was developed and validated for quantitative determination of 11 cannabinoids in different C. sativa samples. Compounds 1 - 11 were baseline separated with an acetonitrile (with 0.05% formic acid) and water (with 0.05% formic acid) gradient at a flow rate of 0.25mL/min on a Waters Cortec UPLC C18 column (100mmx2.1mm I.D., 1.6 mu m). The limits of detection and limits of quantitation of the 11 cannabinoids were below 0.2 and 0.5 mu g/mL, respectively. The relative standard deviation for the precision test was below 2.4%. A mixture of acetonitrile and methanol (80:20, v / v ) was proven to be the best solvent system for the sample preparation. The recovery of all analytes was in the range of 97-105%. A total of 32 Cannabis samples including hashish, leaves, and flower buds were analyzed.