Extraction, isolation and purification of tetrahydrocannabinol from the Cannabis sativa L. plant using supercritical fluid extraction and solid phase extraction

Abstract

The tetrahydrocannabinol (THC) was obtained from Cannabis sativa L. plant material using supercritical fluid extraction (SFE) and solid phase extraction (SPE). SFE was utilized at different pressures (15–33 MPa), temperatures (40–80 °C) and ethanol (EtOH) as co-solvent (0–5%). The effect of extraction parameters on response variables (yield and THC content in raw extract) was evaluated. Keeping both temperature and co-solvent concentration constant at 60 °C and 2% respectively, the highest THC content in raw extracts reaches 37.85% at 33 MPa and 36.18% at 15 MPa. One extract with high THC content was selected and submitted for purification-isolation by SPE. One final fraction with a 90.1% of THC was obtained using a single SPE step. This fraction was analyzed by GC, RP-HPLC and NMR to verify the THC purity. A sequential SFE-SPE process allows to obtain high purity THC from the cannabis plant, which is suitable as quality control material or analytical standard.