Clean Screen XCEL II: A case report on delta-8-THC acetate metabolism
The illicit drug laboratory and analytical toxicology laboratory of Singapore’s Health Sciences Authority received plant material for testing as well as a urine sample from the same case. Visually, the plant sample was consistent with cannabis, however, initial GC-MS analysis detected delta-8-THC and delta-9-THC in low abundance with an unknown substance in much higher concentration. The chemical formula of the unknown was elucidated using LC-Orbitrap-MS analysis and was consistent with THC acetate. NMR analysis confirmed the presence of delta-8-THC acetate. Delta-8-THC acetate is a semi-synthetic cannabinoid derived from delta-8-THC.
The urine sample received with the plant material was extracted using Clean Screen® XCEL II solid phase extraction cartridges. The urine sample (2 mL) was subjected to alkaline hydrolysis prior to extraction. Clean Screen® XCEL II cartridges do not require conditioning, so the urine sample was loaded onto the columns (3 mL, 130 mg) immediately following neutralization of the hydrolysis reaction. The cartridges were washed with hexane and cannabinoids eluted with ethyl acetate/hexane/acetic acid (49:49:2 v/v/v). The sample was evaporated and derivatized using BSTFA with 1% TMCS for GC-MS analysis. The urine sample was confirmed to contain delta-8-THC-COOH. These results prompted an in-vitro study of delta-8-THC acetate using human liver microsomes. After 60 minutes of incubation, delta-8-THC acetate levels dropped to 4% while delta-8-THC-COOH levels increased.
This study supports the assertion that delta-8-THC acetate acts as a prodrug for delta-8-THC which further metabolizes to delta-8-THC-COOH. Clean Screen® XCEL II was designed for the extraction of delta-9-THC-COOH, but this case study shows it can also be used to extract carboxylated metabolites of THC isomers and analogs. These SPE cartridges offer superior recovery and cleanliness over other extraction methods and reduce the amount of solvent and time necessary to perform the extraction by foregoing the need for conditioning.
