Potency testing in marijuana-infused edibles is a problematic task that analytical labs are facing due to the complexity of the involved matrices. Among the most popular matrices are gummy bear candies and brownies. According to one laboratory site, the concentration of active ingredients in the edibles can range from a few parts per million to 3.5 parts per thousand.
This article describes how a procedure was developed to extract active cannabinoid compounds from gummy bears and brownies. The procedure included a simple and fast extraction of the active compounds from the studied foods, and analysis by HPLC-UV using a biphenyl stationary phase chemistry. Cerilliant® cannabinoid standards were used for this experiment. The following compounds were included in the study: cannabidivarinic acid (CBDVA), cannabidivarin (CBDV), cannabigerolic acid (CBGA), cannabigerol (CBG), cannabidiolic acid (CBDA), cannabidiol (CBD), tetrahydrocannabivarin (THCV), cannabinol (CBN), (-)-Δ9 Tetrahydrocannabinol (Δ9-THC), (-)-Δ8- Tetrahydrocannabinol (Δ8-THC), and (-)-Δ9 Tetrahydrocannabinolic acid A (THCAA). This list of 11 different cannabinoids includes several acidic forms; thus HPLC analysis was used in order to quantitate these in their native forms. The HPLC column used was Ascentis® Express Biphenyl, 2.7 μm particle size, which gave the best separation of all 11 compounds in under 13 minutes. The use of this column with Fused-Core® particle architecture resulted in low back pressure, thus a standard pressure HPLC system could be used during this experiment.
The article describes how a method was developed for analysis of active cannabinoid compounds in both brownies and gummy bears. The extraction procedure involved a salting out step into acetonitrile and did not require intensive cleanup. The separation of eleven compounds was achieved on a biphenyl stationary HPLC phase and was completed in 13 minutes.