Liquid chromatography was performed on a Nexera Mikros LC system (Shimadzu Corporation, Kyoto, Japan) composed of one LC-30AD pump, an LC-Mikros microflow pump, a SIL-30AC autosampler, a 6-port switching valve FCV-32AH and a CTO-Mikros column oven with UF-Link. The GmbH, Germany) was mounted on a 6-port switching valve as illustrated in Figure . In a first step, analytes were retained on the column (25°C) using a mixture of H2O/CH3CN (90/10; v/v), 0.1 % formic acid at 100 μL/min. After 0.25 min, the valve was switched and the analytes eluted in back-flush mode to the mass spectrometer using H2O/CH3CN (80/20; v/v), 0.1 % formic acid at 100 μL/min. The total run time was of 1 min with an injection volume of 10 μL. Data were acquired and processed using LabSolutions (version 5.99 SP2, Shimadzu Corporation, Kyoto, Japan). Table summarizes the LC, MS and vDMS optimized parameters for the analysis of eight drugs of abuse and five cannabinoids.