Metabolic Profiles of 5F-MDMB-PICA in Human Urine, Serum and Hair Samples Using LC-Q Exactive HF-MS

In 2020, 5F-MDMB-PICA (5F-MDMB-2201) was one of the most common synthetic cannabinoids (SCs) identified in drugs seized by the Beijing Drug Control Agency, and it was categorized as Schedule II by the United Nations Office on Drugs and Crime in March 2020. It is difficult to detect 5F-MDMB-PICA in biological matrices due to its fast metabolic rate in vivo. In this work, 5F-MDMB-PICA metabolic profiles were investigated by liquid chromatography--quadrupole exactive high field orbitrap mass spectrometer (LC-Q Exactive HF MS), with accurate mass measurements in human urine, serum and pubic hair. To obtain intact metabolites, solid-phase extraction for urine and serum and direct ultrasonic extraction for pubic hair were applied to clean the samples without enzymatic hydrolysis. The differences in 5F-MDMB-PICA metabolism in the three different matrices were compared for the first time to determine the best detection biomarkers for monitoring 5F-MDMB-PICA misuse. Urine samples were determined to be the preferred biological material for identifying 5F-MDMB-PICA abuse. Forty-seven intact metabolites were detected in human urine, the ester hydrolyzed with glucuronidated metabolite in urine samples can be used as the primary biomarker to identify drug misuse. Fifteen metabolites were found in serum samples. Ester hydrolysis was considered to be the major metabolic pathway, and a large number of metabolites were involved with it. Zero metabolites apart from the parent drug were detected in pubic hair samples. Twenty-eight new metabolites and their metabolic pathways were characterized and tentatively identified by LC-QE-HF-MS, and a new potential biomarker (M5 ester hydrolysis + propionic acid) was also identified.