Hair analysis for JWH-018, JWH-122, and JWH-210 after passive in vivo exposure to synthetic cannabinoid smoke

Abstract

Hair analysis is often used to confirm abstinence from drug use. However, interpretation of hair analysis results can be challenging, particularly with regard to smoked substances like synthetic cannabinoids, because hair can be contaminated by side-stream smoke. In this study, we measured the concentrations of synthetic cannabinoids in scalp hair after exposure to side-stream smoke from a cigarette containing the synthetic cannabinoids JWH-018, JWH-122, and JWH-210. Three participants exposed their hair to the side-stream smoke once each working day for 3 weeks to mimic realistic conditions experienced by consumers of these drugs. Two other participants exposed their hair once to the side-stream smoke of one cigarette. Scuba regulators with external air supply were used to avoid inhalation of smoke. Hair segments and wash solutions were analyzed by liquid chromatography–tandem mass spectrometry. The highest measured concentrations were 70 pg/mg of JWH-018, 260 pg/mg of JWH-122, and 950 pg/mg of JWH-210 in distal hair segments collected at the end of the exposure period. At 2–3 weeks after the end of the repeated exposure, all three synthetic cannabinoids were detected in the hair samples of both participants with longer hair. In these samples, the ratio of cannabinoid amount in acetone wash to that in hair was below 0.5 for all synthetic cannabinoids, which could be interpreted as evidence of consumption. However, with the nonconsumption of synthetic cannabinoids by our study participants being confirmed by urine testing, it is apparent that even high substance concentrations in hair samples do not prove consumption and can be explained by external contamination after contact with synthetic cannabinoids alone.