Prevalence of carboxy-Δ 8 -tetrahydrocannabiniol in antidoping samples.

Δ 9 -Tetrahydrocannabinol (Δ 9 -THC) is usually the primary psychoactive agent in cannabis preparations. Recently, products containing another isomer, Δ 8 -tetrahydrocannabinol (Δ 8 -THC), have become available for sale. Δ 8 -THC exists naturally in the cannabis plant at very low concentrations; hence, the Δ 8 -THC present in most of the above-mentioned products is likely to be manufactured synthetically. A surge in popularity of these products, coupled with little oversight to ensure purity and potency, has led to reports of adverse events. Workplace drug testing programs as well as many sporting organizations prohibit the use of cannabinoids. Carboxy-Δ 9 -THC (Δ 9 -THC-COOH) is the targeted urinary metabolite for detection of cannabis use. The proliferation of products containing Δ 8 -THC, which metabolizes to Δ 8 -THC-COOH, presents analytical complexity with respect to separation and quantification of the individual isomers as well as legal complexity with respect to lack of clarity around the legal status of Δ 8 -THC. This study aims to estimate the prevalence of Δ 8 -THC use in the athlete community by monitoring for Δ 8 -THC-COOH in samples collected for antidoping. A high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) method was utilized to resolve Δ 8 and Δ 9 -THC-COOH. One thousand samples with a presumptive Δ 9 -THC-COOH finding in routine screening were analyzed by the above LC-MS/MS method. Approximately 12% of samples contained Δ 8 -THC-COOH at relative abundances between 5% and 100% of total carboxy-THC content.