Nontargeted SWATH acquisition for identifying 47 synthetic cannabinoid metabolites in human urine by liquid chromatography-high-resolution tandem mass spectrometry

Clandestine laboratories constantly produce new synthetic cannabinoids to circumvent legislative scheduling efforts, challenging and complicating toxicological analysis. Sundstrom et al. (Anal Bioanal Chem 405(26):8463-8474, [9]) and Kronstrand et al. (Anal Bioanal Chem 406(15):3599-3609, [10]) published nontargeted liquid chromatography, high-resolution, quadrupole/time-of-flight mass spectrometric (LC-QTOF) assays with validated detection of 18 and 38 urinary synthetic cannabinoid metabolites, respectively. We developed and validated a LC-QTOF urine method for simultaneously identifying the most current 47 synthetic cannabinoid metabolites from 21 synthetic cannabinoid families (5-fluoro AB-PINACA, 5-fluoro-AKB48, 5-fluoro PB-22, AB-PINACA, ADB-PINACA, AKB48, AM2201, JWH-018, JWH-019, JWH-073, JWH-081, JWH-122, JWH-200, JWH-210, JWH-250, JWH-398, MAM2201, PB-22, RCS-4, UR-144, and XLR11). beta-Glucuronidase-hydrolyzed urine was extracted with 1-mL Biotage SLE+ columns. Specimens were reconstituted in 150-mu L mobile phase consisting of 80 % A (0.1 % formic acid in water) and 20 % B (0.1 % formic acid in acetonitrile). Fifty microliters was injected, and SWATH (TM) MS data were acquired in positive electrospray mode. The LC-QTOF instrument consisted of a Shimadzu UFLCxr system and an ABSciex 5600+ TripleTOFA (R) mass spectrometer. Gradient chromatographic separation was achieved with a Restek Ultra Biphenyl column with a 0.5-mL/min flow rate and an overall run time of 15 min. Identification criteria included molecular ion mass error, isotopic profiles, retention time, and library fit criteria. Limits of detection were 0.25-5 mu g/L (N = 10 unique fortified urine samples), except for two PB-22 metabolites with limits of 10 and 20 mu g/L. Extraction efficiencies and matrix effects (N = 10) were 55-104 and -65-107 %, respectively. We present a highly useful novel LC-QTOF method for simultaneously confirming 47 synthetic cannabinoid metabolites in human urine.