Examination of analytical method for synthetic cannabinoids in human serum by solid-phase dispersive extraction-GC/MS

Abstract

  In order to prove synthetic cannabinoid abuse, it is necessary to detect intact synthetic cannabinoids or their metabolites from such biological samples as urine or blood. Generally, blood is used as the biological sample because it is usually difficult to detect intact synthetic cannabinoids in urine. Furthermore, a rapid and accurate method for the detection of synthetic cannabinoids in the biological sample is required. Therefore, we examined the applicability of solid-phase dispersive extraction (SPDE)-GC/MS in the rapid detection of intact synthetic cannabinoids in blood. We chose seven synthetic cannabinoids designated as narcotics. To determine the optimum operating conditions for SPDE, we selected Oasis^® HLB as the solid-phase material for pre-treatment and filled it with 10 mg into the equipment, and acetone as the eluent. The pre-treatment resulted in 80-100% recovery. Furthermore, the pre-treatment time was significantly reduced in SPDE compared to solid-phase extraction (SPE). In addition, the pre-treatment protected operators from unnecessary exposure, reduced cross-contamination of chemicals, and decreased operation complexity. The limit of detection (S/N>3) of JWH-018, JWH-122, cannabicyclohexanol (CCH), XLR-11, and AM2201 was 2.5 ng/mL, and that of JWH-073 and MAM-2201 was 5 ng/mL. The limit of quantification (S/N>10) of JWH-018, JWH-122, CCH, XLR-11, and AM2201 was 5 ng/mL, and that of JWH-073 and MAM-2201 was 10 ng/mL. The average recoveries of the seven synthetic cannabinoids from pooled serum samples spiked at 25 and 450 ng/mL were 76.9-107.4% (SD: 6.4-10.7%) and 63.1-89.6% (SD: 3.9-8.2%), respectively. (SPDE)-GC/MS was proven to be a useful method for detecting intact synthetic cannabinoids in blood.