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

Abstract

Cannabinoids are a group of terpenophenolic compounds in the medicinal plant Cannabis sativa (Cannabaceae family). Cannabigerolic acid, Δ 9 -tetrahydrocannabinolic acid A, cannabidiolic acid, Δ 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 Δ 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 0.25 mL/min on a Waters Cortec UPLC C18 column (100 mm × 2.1 mm I.D., 1.6 μm). The limits of detection and limits of quantitation of the 11 cannabinoids were below 0.2 and 0.5 μg/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.