Simultaneous Determination of Selegiline, Desmethylselegiline, R/S-methamphetamine, and R/S-amphetamine on Dried Urine Spots by LC/MS/MS: Application to a Pharmacokinetic Study in Urine.

Lizhu Chen,Baohua Shen,Ping Xiang,Gengli Duan,Yingjia Yu,Xin Wang

doi:10.3389/fchem.2019.00248

Lizhu Chen, Baohua Shen + Show 4 more

Open Access

https://doi.org/10.3389/fchem.2019.00248

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Abstract

Objective: Chiral analysis is a crucial method to differentiate selegiline intake from drug abuse. A dried urine spot (DUS) analytical method based on spotting urine samples (10 μL) onto dried spot collection cards, and followed by air-drying and extraction, was developed and validated for the determination of selegiline, desmethylselegiline, R/S-methamphetamine, and R/S-amphetamine.Methods: Methanol (0.5 mL) was found to be the ideal extraction solvent for target extraction from DUSs under orbital-horizontal stirring on a lateral shaker at 1,450 rpm for 30 min. Determinations were performed by direct electrospray ionization tandem mass spectrometry (ESI-MS/MS) under positive electrospray ionization conditions using multiple reaction monitoring mode. The chromatographic system consisted of a ChirobioticTM V2 column (2.1 × 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 50 to 5,000 ng/mL, with r > 0.995 for all analytes, imprecisions ≤ 15% and accuracies between −11.4 and 11.7%. Extraction recoveries ranged from 48.6 to 105.4% with coefficients of variation (CV) ≤ 13.7%, and matrix effects ranged from 45.4 to 104.1% with CV ≤ 10.3%. The lower limit of quantification was 50 ng/mL for each analyte. The present method is simple, rapid (accomplished in 12 min), sensitive, and validated by a pharmacokinetic study in human urine collected after a single oral administration of SG.

Highlights

Dried spot cards have been reported as an easy, simple, fast, and inexpensive sampling strategy for specimen collection, transport, and storage (Li and Tse, 2010; Déglon et al, 2012; Demirev, 2013; Zimmer et al, 2013)
No significant interference was observed at the retention time of the analytes and internal standard (IS), indicating acceptable method selectivity
No carryover effect was observed in the blank DUS samples measured directly after the highest calibration standard

Summary

Introduction

Dried spot cards have been reported as an easy, simple, fast, and inexpensive sampling strategy for specimen collection, transport, and storage (Li and Tse, 2010; Déglon et al, 2012; Demirev, 2013; Zimmer et al, 2013). The applications of dried spot cards have been extensively reported to include biomarker analysis and drug testing in blood (Barfield et al, 2008; Spooner et al, 2009; Michely et al, 2017; Namdev et al, 2018). Urine is the most widely employed matrix among the different biological specimens for the analysis of drugs and metabolites because of ease of collection and higher levels of drugs and metabolites, in comparison to the values found in serum/blood and saliva (Moeller et al, 2008). The application of dried urine spot (DUS) technology has increased gradually, mainly in clinical diagnostics and forensic toxicology analysis (Al-Dirbashi et al, 2011; Forman et al, 2012; Lee et al., 2013; Otero-Fernández et al, 2013).

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