Evaluation of an On-site Drug-testing Device for the Detection of Synthetic Cannabinoids in Illegal Herbal Products

Recently, illegal herbal or liquid products containing psychoactive compounds have been a serious problem damaging human health and causing numerous traffic accidents. Reports indicate that most of those herbal products contain various types of synthetic cannabinoids. There are many on-site drug-testing devices; however, synthetic cannabinoids are not targeted compounds for such devices. In this study, we evaluated the on-site drug-testing device "K2/Spice Test" for the detection of 12 different types of 38 synthetic cannabinoids (including 13 naphthoylindole-type synthetic cannabinoids) and a natural cannabinoid (Δ(9)-tetrahydrocannabinol). Although this device is primarily used for the detection of metabolites of naphthoylindole-type synthetic cannabinoids in urine samples, we applied it to detect synthetic cannabinoids in illegal herbal products for rapid screening analyses. As a result of the on-site examination of synthetic cannabinoids, 10 naphthoylindole-type synthetic cannabinoids [five narcotics (JWH-018, JWH-073, AM-2201, MAM-2201, and JWH-122); five designated substances (JWH-015, JWH-200, AM-1220, JWH-019, and JWH-020)], and two other types of synthetic cannabinoid [designated substances (a benzoylindole AM-694 and a naphthoylnaphthalene CB-13)] showed positive results (the limit of detection ranged from 50 to 250 μg/mL). Furthermore, MeOH extracts of illegal herbal products containing naphthoylindole-type synthetic cannabinoids also showed positive results (the limit of detection ranged from 2.5 to 10 mg herbal products/mL). Therefore, we found that this device may be useful for the on-site examination of some naphthoylindole-type synthetic cannabinoids not only in urine samples but also in illegal herbal products.