Simultaneous detection of 87 synthetic cannabinoids and their metabolites in urine samples by UHPLC-MS/MS and application to 109 authentic forensic cases

Abstract

Synthetic cannabinoids (SCs) have emerged on the designer drug market at an alarming rate in recent years. Consequently, the current methods for detecting SCs and their metabolites in urine require further optimization. An efficient and rapid quantitative UHPLC-MS/MS method was developed for the detection of 87 SCs and their metabolites in urine. Urine (0.1 mL) was incubated for 30 min at 55 °C by adding 10 μL β-glucuronidase and then processed by acetonitrile protein precipitation. A Waters Acquity UPLC HSS T3 column (100 mm × 2.1 mm,1.8 µm) was used for chromatographic separation. Mobile phase A was 20 mmol/L ammonium acetate, 0.1% formic acid, and 5% acetonitrile in water, and mobile phase B was acetonitrile. The limits of detection (LOD) ranged from 0.02 ng/mL to 2 ng/mL and the limits of quantitation (LOQ) ranged from 0.05 ng/mL to 5 ng/mL. The accuracy was in the range of 88.6% to 112%. The relative standard deviations of the intraday and interday imprecisions were in the range of 1.09% to 18.7%, and the recoveries were in the range of 16.4% to 102% and the matrix effect ranged from 70.4% to 114%. After full validation, the method showed good selectivity, accuracy, precision, linearity, and stability within the calibration range. It's simple, rapid and covers a variety of analytes in forensic cases. It was successfully applied to urine samples from 109 suspected SCs users. The most frequently metabolites detected in authentic urine samples in this study were MDMB-4en-PINACA butanoic acid metabolite and ADB-BUTINACA acid metabolite.