Quantification of AB-CHMINACA Metabolites in Urine by Validated Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry Method

Abstract

Background: Synthetic cannabinoids (), chemically classified as psychoactive substances, target the endocannabinoid system by binding to CB1 and CB2 receptors. Unlike Δ9-tetrahydrocannabinol (Δ9-THC), they act as full agonists at these receptors and generally exhibit significantly greater potency and efficacy. Despite being marketed as “Herbal blends,” SCs are associated with severe intoxications and fatalities. Due to rapid metabolic transformation, the parent SCs are not detectable in urine samples, so analytical methods must rely on the identification and quantification of their metabolites. Objectives: The objective of this study was to develop a targeted UHPLC-MS/MS method for the quantitative analysis of AB-CHMINACA’s metabolites in urine. Methods: Urine samples were hydrolyzed with β-glucuronidase and extracted through liquid-liquid extraction using ethyl acetate-isopropanol ammonium hydroxide. UHPLC analysis–MS/MS in positive electrospray ionization (ESI) mode with multiple reaction monitoring (MRM) detection was performed on a C18 column. Results: The method demonstrated good linearity (2-100 ng/mL, r² >0.995), high recovery (~92%), minimal matrix effects, and acceptable accuracy and precision (≤11.8% RSD). LOD and LLOQ were 1 and 2 ng/mL, respectively, with no carryover and sufficient stability. Conclusions: The developed UHPLC-MS/MS method provides a sensitive, simple, and rapid approach for the reliable identification of AB-CHMINACA metabolites in urine, demonstrating its suitability for forensic and clinical toxicology applications.