Volume 47, Issue 6 (November 2002)
Enantiomeric Separation of Methamphetamine and Related Analogs by Capillary Zone Electrophoresis: Intelligence Study in Routine Methamphetamine Seizures
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.