A Screening Method for Major Metabolites of the Active Ingredients of K2: JWH-018 and JWH-073 in Human Urine Using LC-MS/MS

JWH-018 and JWH-073 are two main active ingredients of K2. They act as cannabinoid agonist at both CB1 and CB2 receptors. When smoked or orally ingested, K2 produces some effects that are similar to those of cannabis. Several countries and few states in the US have placed legal restrictions on these compounds.

It is relatively challenging to establish a screening method for K2 in human urine because of the multiple active ingredients along with the relatively short half-life for the parent compounds. The most effective screening method should include the detection of active ingredients as well as their metabolites. To resolve these challenges, JWH-018 and JWH-073 were individually incubated in human liver microsomes, and the in vitro metabolite pathways were identified for each of these active ingredients.

Results were used to build a targeted detection method using LC-MS/MS operated in Multiple Reaction Monitoring (MRM) mode. The LC-MS/MS screening method was developed on the 4000 QTRAP system to further take advantage of an MS/MS spectral library. The use of LC-MS/MS allowed for enough sensitivity to detect K2 metabolites in human urine and results were automatically confirmed using MS/MS library searching.