The goal of this project was to develop a method to quantify cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) in commercially available CBD oils. The FDA limits CBD products to containing less than 0.3% THC (3 mg/mL), as THC is the psychoactive component. In the developed method, CBD oils are first diluted with ethyl acetate (including a known concentration of anthracene as an injection standard). The mixture is then derivatized using BSTFA which replaces labile hydrogens with TMS, preventing decomposition of the cannabinoids during the subsequent analysis by Gas Chromatography-Mass Spectrometry (GC-MS). Calibration curves were constructed to quantify CBD and THC concentrations relative to peak area. During method development, the BSTFA derivatization procedure was optimized to ensure complete derivatization of CBD and THC even in the presence of the commercial oil matrix. The calibration curves were prepared by drying a known volume of CBD and THC standards (Supelco) under a flow of nitrogen. Samples were reconstituted in ethyl acetate (containing the injection standard), derivatized, and diluted with ethyl acetate prior to GC-MS analysis. Three commercial CBD oils were studied: PureKana, FABCBD, and Charlotte’s Web. The oil samples were prepared by taking 1 mL of CBD Oil and mixing it with 4 mL of ethyl acetate containing the injection standard. 25 μL of the oil mixture was mixed with 50 μL of BSTFA-TMCS (Supelco) and heated for 90 min at 70 °C prior to analysis by GC-MS . The GC-MS injection port was set at 250 °C. The Shimadzu SHRXI-5MS column was held at 250 °C for 15 min followed by a ramp at 5 °C/min to 300 °C then held for 15 min. This 40-min program was used for all oil samples studied. The reported and experimentally-determined concentrations of CBD and THC are shown in the Table below. Future work will focus on extending the THC calibration curve into the low μg/mL range to confirm the THC concentrations determined.

Development of a direct analysis method for the quantification of cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) in commercial CBD oils

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.