Screening and confirmation methods for the qualitative identification of nine phytocannabinoids in urine by LC-MS/MS.

Qualitative liquid chromatography tandem mass spectrometry (LC-MS/MS) methods were developed and validated to screen and confirm the presence of nine phytocannabinoids in urine. The nine phytocannabinoids targeted in the methods included Δ9-tetrahydrocannabinol (THC), 11-hydroxy-THC, 11-nor-9-carboxy-THC, cannabidiol, 7-carboxy cannabidiol, cannabinol, cannabigerol, Δ9-tetrahydrocannabivarin (THCV), and 11-nor-9-carboxy-THCV. The methods presented use a rapid, single-step enzymatic hydrolysis followed by solid-phase extraction and LC-MS/MS analysis. Limits of detection were established at 1 µg/L for non-carboxylated analytes and 5 µg/L for carboxylated analytes. The screening and confirmation methods were validated and implemented in the analysis of authentic case samples. These methods can assist forensic, medicolegal, or medical compliance investigations as the presence of phytocannabinoids, or lack there-of, may be used to help differentiate cannabis (hemp, marijuana) use from synthetic THC (dronabinol) exposure.