Characterization of Extensive 2-Fluorodeschloroketamine (2F-DCK) Metabolism in Pooled Human Liver Microsomes (pHLM), Urine, and Hair from an Addicted Patient Using High-Resolution Accurate Mass (HRAM) Spectrometry.

Abstract

2-Fluoro-deschloroketamine (2F-DCK) is a ketamine derivative involved in acute intoxications and deaths. The aim of this study is to investigate its metabolism using pHLM, and to apply it to authentic samples (urine, hair, seized materials) from a drug user. 2F-DCK (100 µM) incubates with pHLM were analyzed by LC-HRAM (Q-Exactive, Thermo Fisher Scientific®) according to a previously published protocol. Spectra annotation was performed using Compound Discoverer® software and the metabolic scheme was drawn using Chemdraw software. Urine (200 µL) and hair (previously decontaminated using dichloromethane and segmented into 3 segments: A 0-3 cm, B 3-6cm, C 6-9cm) were extracted with a mixture of hexane/ethyl acetate (1:1) and chloroform/isopropanol (4:1). 10 µL of both reconstituted residues were analyzed by LC-HRAM. Hair was also analyzed by LC-MS-MS (TSQ Vantage, Thermo Fisher Scientific®) for 2F-DCK and DCK quantification. The two presumed 2F-DCK crystals consumed by the patient were dissolved in methanol (1 mg/mL) and 10 µL were analyzed by LC-MS-MS (Quantum Access Max, Thermo Fisher Scientific®). Twenty-six putative 2F-DCK metabolites were identified, 15 being reported for the first time. Thirteen metabolites were detected in pHLM, 10 confirmed in both the patient's urine and hair, and all found in at least one of the 2 samples. 23 metabolites were detected in urine, and 20 in hair. Our research confirms the reliability of nor-2F-DCK as a target analyte and suggest OH- dihydro-nor-2F-DCK and dehydro-nor-2F-DCK as new target analytes in urine and hair, respectively. This is the first study to report deschloroketamine as a 2F-DCK metabolite using pHLM and to determine its concentrations in hair (A/B/C, 885/1500/1850 pg/mg) following chronic use. Finally, the two seized crystals contained 2F-DCK at 67% and 96% with traces of deschloroketamine (0.4% and 0.6%) related to cross-contamination by container exchange.