Enantiomeric Separation of Methamphetamine and Related Analogs by Capillary Zone Electrophoresis: Intelligence Study in Routine Methamphetamine Seizures

Abstract

A method for simultaneous enantiomeric separation of ephedrine, pseudoephedrine, and methamphetamine (MA) in a single run by simple capillary zone electrophoresis (CZE) with β-cyclodextrin as a chiral selector is described. The effects of the buffer pH, phosphate concentration, β-cyclodextrin concentration, voltage and temperature on the peak resolution were examined. Good enantiomeric resolution was attained for each analyte under our optimized conditions: 15 mM β-cyclodextrin, 300 mM NaH2PO4 at pH 2.5 with an uncoated capillary (64.5 cm × 50 m), applied potential at 20 kV and temperature at 30°C. Ultraviolet (UV) detection at a fixed wavelength (200 nm) was employed using a diode array detector. Using phentermine as an internal standard, migration times for all analytes are reproducible within 0.1% for intra-day and 0.6% for inter-day runs. Application of this method to the analysis of confiscated drugs is discussed.

The application of capillary electrophoresis for enantiomeric separation of N,N-dimethylamphetamine and its related analogs: Intelligence study on N,N-dimethylamphetamine samples in crystalline and tablet forms

“…The remaining contained a variable combination of the two enantiomers (varying from À41 to À92% ee based on L-MA). Similar results were also obtained in previous studies [8,15]. One possible explanation is physical mixing of the two enantiomers in different proportions.…”

“…The previously reported CE conditions [8] (i.e. electrolyte consisting of 15 mM b-CD and 300 mM NaH 2 PO 4 at pH 2.5, applied potential at 20 kV and with the temperature at 30 8C) were applied for chiral separation of DL-E, DL-PE, DL-Me-E, DL-MA and DL-DMA.…”

“…Temperature is one of the important parameters to be considered since it can affect several parameters such as mobility of analytes, the kinetic and thermodynamic of the inclusion-complexation with CDs [11]. Capillary temperatures between 20 and 30 8C were tested [8]. At 20 8C, no significant improvement in peak resolution was observed, and also the run time was longer.…”

“…In fact, previous study in our laboratory has successfully demonstrated the use of CE for enantiomeric separation of DL-MA and its related compounds (i.e. DL-E and DL-PE) [8]. In this study, a new CE method for the simultaneous chiral separation of DL-DMA, DL-MA, DLephedrine, DL-PE and DL-Me-E was developed.…”

A rapid and convenient LC/MS method for routine identification of methamphetamine/dimethylamphetamine and their metabolites in urine

“…Methamphetamine (MA), both in high purity crystal or in tablet forms, continues to be one of the popular drugs of abuse in Hong Kong [1]. Recently, some drug seizures received by our Laboratory were found to contain samples physically similar to MA.…”