Quantitative measurement of XLR11 and UR-144 in oral fluid by LC-MS-MS.

Availability and consumption of synthetic cannabinoids have risen recently in the USA and Europe. These drugs have adverse effects, including acute psychosis and bizarre behavior. In 2012, the United States Drug Enforcement Agency permanently banned five of the synthetic cannabinoids and in 2013, temporarily added XLR11, UR-144 and AKB48 to Schedule I of the Controlled Substances Act. As synthetic cannabinoid strains are added to the Schedule I list, new strains are being introduced into the market. XLR11 and UR-144 are two of the most recent additions to the synthetic cannabinoid drug class. To test collected oral fluid samples for XLR11 and UR-144, we developed a bioanalytical method that initially purifies the sample with solid-phase extraction and then quantitatively identifies the drugs with ultra-high-performance liquid chromatography-tandem mass spectrometry. The method was validated according to United States Food and Drug Administration guidelines and Scientific Working Group for Forensic Toxicology guidelines and the validation data showed that the method is an accurate, precise, robust and efficient method suited for high-throughput toxicological screening applications. We tested human subject samples with the developed method and found the presence of parent drugs (XLR11 and UR-144), their metabolites and their pyrolysis products in oral fluid.