Fast and Sensitive Chiral Analysis of Amphetamines and Cathinones in Equine Urine and Plasma Using Liquid Chromatography Tandem Mass Spectrometry

Caroline C Wang,Max O Wolk,Tim R Krueger,Alisha Lester,Aaron Simonson,Terry L Wells,Petra Hartmann-Fischbach,Nick J Hidlay

doi:10.4236/ajac.2015.613094

Caroline C Wang, Max O Wolk + Show 6 more

Open Access

https://doi.org/10.4236/ajac.2015.613094

Copy DOI

Abstract

A simple, rapid, sensitive and reproducible method for enantiomer analysis of methamphetamine, amphetamine, cathinone and methcathinone was developed and validated. The compounds were extracted from equine plasma and urine using a fast liquid-liquid extraction procedure. Only one milliliter plasma and one hundred microliter urine sample is needed for analysis. The extraction procedure had good recovery (>70%) and the matrix effect was negligible. Enantiomer differentiation and confirmation were achieved using liquid chromatography with chiral stationary phase and mass spectrometry detection. The method demonstrated excellent reproducibility with intra-day and inter-day precision of lower than 5%. The lower limits of detection for all of the compounds studied here were at low pg/mL level for both plasma and urine. This is the first report of the analysis of four chiral compounds in equine plasma and urine. Routine application was demonstrated for (S)- and (R)-enantiomer differentiation.

Highlights

Methamphetamine, amphetamine, cathinone and methcathinone are powerful central nerve system (CNS) stimulants and are abused in many countries [1]-[8]
According to Uniform Classification Guidelines for Foreign Substances and Recommended Penalties and Model Rules from Association and Racing Commissioner International (RCI), methamphetamine, amphetamine, cathinone and methcathinone are all Class I drugs based on their ability to influence the outcome of a horse race
The aim of our research was to develop and validate a simple, fast, sensitive and selective Liquid chromatography mass spectrometry (LC-MS)/MS method for confirmation and enantiomer separation of amphetamines and cathinones extracted from equine blood or urine

Summary

Introduction

Methamphetamine, amphetamine, cathinone and methcathinone are powerful central nerve system (CNS) stimulants and are abused in many countries [1]-[8]. According to Uniform Classification Guidelines for Foreign Substances and Recommended Penalties and Model Rules from Association and Racing Commissioner International (RCI), methamphetamine, amphetamine, cathinone and methcathinone are all Class I drugs based on their ability to influence the outcome of a horse race. Amphetamine is a metabolite of methamphetamine [8] [9] Cathinone and methcathinone both have a β-keto group and they are structurally close to amphetamine. These four compounds all contain a chiral center and have S and R enantiomers. The CNS stimulant activities increase in the order of (S)-amphetamine, (S)-cathinone, (S)-metham-phetamine and (S)-methcathinone [1]. Unambiguous identification of enantiomers can be extremely useful in clinical, forensic, and toxicological applications to distinguish illicit consumption, origin and the metabolism of the target compound [8]-[13]

Objectives

Methods

Results