Extraction and UPLC Analysis of THC, THCA, CBN, CBD, and CBDA from Hemp Flower
With the passing of the 2018 Farm Bill legalizing hemp, new hemp producers are entering the market with new and large hemp crops. This increase in raw material has led to the need for efficient extraction methods to assess the potency of the material. For cannabis to be defined as hemp the total THC content must be at, or lower than, a specific level, therefore accurate determination of cannabinoid content is essential to the industry. Cannabis is a difficult and complex matrix to analyze. Extraction and cleanup generally go hand in hand utilizing sorbents to remove undesirable constituents from the total extract. Typically, the QuEChERS method is used to extract the cannabinoid content from cannabis. This method has several disadvantages, including multiple sample transfers, substantial waste generation, and its manual nature. In this study, the EDGE® was used to extract cannabinoids from hemp flower and was shown to be more efficient than traditional methods at both low and high temperatures.
In light of the legalization of industrial hemp, methods to examine the potency of cannabinoids from cannabis plants and products are necessary. Potency testing is crucial for assessing the legality of the material. The major compounds of interest in cannabis are Δ9-tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabinol (CBN), cannabidiol (CBD), and cannabidiolic acid (CBDA). Currently, regulations require industrial hemp to contain less than 0.3% of THC and THCA combined on a dry weight basis. Furthermore, the cannabinoid content of cannabis is important for its use medicinally or recreationally. Cannabis that contains high total THC content and low total CBD (sum of both CBD and CBDA) is typically used recreationally and is sold at a higher price, while cannabis that has lower total THC content and higher total CBD is usually for medicinal purposes.
Cannabis, in all its forms, has proven to be a challenging matrix to analyze. Typically, cannabis flower is extracted to determine potency using the QuEChERS method. However, QuEChERS is time consuming and tedious, as it is a manual method that requires multiple sample transfers and creates substantial waste. Using the EDGE, extractions are performed in a single vessel, the Q-Cup™, in one automated step without the use of cleanup materials. The EDGE also filters the extract, yielding a cooled sample ready for direct liquid chromatography analysis.