Identification of 11-nor-Δ-8-tetrahydrocannabinol-9-carboxylic acid in postmortem urine

J Anal Toxicol. 2023 Apr 7:bkad023. doi: 10.1093/jat/bkad023. Online ahead of print.


Laws concerning the growing, selling, and consuming cannabis and its related products have been changing considerably over the last few years. The legalization of hemp in 2018 sparked an interest in Δ-9-tetrahydrocannabinol (Δ-9-THC) isomers and analogs that are derived from hemp and sold with minimal oversight. One example is Δ-8-tetrahydrocannabinol (Δ-8-THC). Although less potent than Δ-9-THC, Δ-8-THC is gaining popularity and can easily be found where cannabis-related products are sold. The forensic toxicology laboratory at the University of Florida routinely tests decedents for 11-nor-Δ-9-tetrahydrocannabinol-9-carboxylic acid (Δ-9-THC-acid), the primary metabolite of Δ-9-THC. Urine samples from approximately 900 decedents were received by the laboratory between mid-November 2021 to mid-March 2022 and subjected to CEDIA™ immunoassay testing. Subsequent confirmation of 194 presumptive positive samples was performed by gas chromatography-mass spectrometry (GC-MS). A peak eluting immediately after Δ-9-THC-acid was identified as 11-nor-Δ-8-tetrahydrocannabinol-9-carboxylic acid (Δ-8-THC-acid), a metabolite of Δ-8-THC, in 26 of those samples (13%). Six (6) of the Δ-8-THC-acid positive samples were positive for Δ-8-THC-acid only. Other toxicological findings were consistent with poly-drug use including fentanyl/fentanyl analogs, ethanol, cocaine, and methamphetamine. There has been an emergence of Δ-8-THC use as indicated by the presence of Δ-8-THC-acid in 26 of 194 presumptive positive cases during a four-month period. The majority of individuals were White males with a history of drug and/or alcohol use. Δ-9-THC-acid, as well as other drugs, were often present. Given the psychoactive potential and availability of Δ-8-THC, monitoring Δ-8-THC-acid in decedents is important to characterize risk and prevalence of Δ-8-THC use.

PMID:37026691 | DOI:10.1093/jat/bkad023