Purpose It is crucial for forensic analysis to differentiate clinical use from illegal abuse. Selegiline (SG) is mainly metabolized to desmethylselegiline (DM-SG), R -(−)-methamphetamine (R-MA) and R-(−)amphetamine (R-AM); while abused methamphetamine and amphetamine mainly contain the S -(+)-form. The aim of this study was to simultaneously determine SG, DM-SG, R / S -MA, and R / S -AM in human oral fluid (OF) and to differentiate clinical use from illegal use. We also aim to apply the present method to the OF samples from authentic cases in forensic toxicology. Methods Liquid–liquid extraction and liquid chromatography-tandem mass spectrometry operating in positive ion multiple-reaction monitoring mode were utilized. The chromatographic system consisted of a Chirobiotic TM V2 column (2.1 mm × 250 mm, 5 μm) and a mobile phase of methanol containing 0.1% (v/v) glacial acetic acid and 0.02% (v/v) ammonium hydroxide. Results and conclusions The calibration curves were linear from 1 to 100 ng/mL, and r > 0.995 for all analytes with imprecisions ≤ 15% and accuracy between 85 and 115%. Extraction recoveries ranged from 46.3 to 104.7% with coefficient of variation (CV) ≤ 10.3% and matrix effects (MEs) ranged from 47.4 to 114.8% with CV ≤ 12.9%. The lower limit of quantification was 0.2 ng/mL for SG and DM-SG and 1.0 ng/mL for S-MA, R-MA, S-AM and R-AM. The present method is simple, rapid (accomplished in 12 min), sensitive, and validated by authentic samples.
Background Chiral analysis is a crucial way to differentiate selegiline (SG) intake from drug abuse. Oral fluid (OF) has been successfully used as an alternative matrix for blood testing in several pharmacokinetic studies. Objective The aim of this study is to describe the pharmacokinetics of SG and its main metabolites in OF after a single oral administration of SG which is meaningful for results interpretation in forensic analysis. Methods Ten milligrams of SG were orally administered to 8 volunteers, and OF samples were collected for up to 96 hours by having participants spit into polypropylene tubes without stimulation. These samples were submitted to liquid–liquid extraction before analysis by liquid chromatography–tandem mass spectrometry operating in positive ion multiple-reaction monitoring mode. Results and conclusions After oral administration, each analyte could be detected in OF specimens from all volunteers with an initial detection time of 0.50 hours. The C max values of SG, R-MA, R-AM and DM-SG were 50.93–992.67 ng/mL, 29.78–653.64 ng/mL, 8.22–150.15 ng/mL, and 4.34–16.25 ng/mL, respectively, at 0.5 hours, 1–11 hours, 1.5–11 hours, and 0.5–6 hours post dose. The times when the compounds were last determined in OF were 5–24 hours for SG, 52–96 hours for R-MA, 31–96 hours for R-AM, and 13–31 hours for DM-SG after oral administration. There is a period of time in OF in which only MA and AM are present without SG and DM-SG after a single dose of SG. The pharmacokinetic data could provide supplementary interpretation for OF tests in forensic science and drug treatment programs.
危险品化学品经营许可证（带存储）