Abstract
High performance liquid chromatography (HPLC) method using Pirkle-type chiral stationary phase (CSP) was developed for the separation of the enantiomers of ephedrine, norephedrine and pseudoephedrine, which were central nervous stimulants. The resolutions were made using normal-phase methodology with a mobile phase consisting of n-hexane, 1,2-dichloroethane and methanol. Conditions for the experiments were optimized, including the content of methanol, 1,2-dichloroethane and acetic acid in mobile phase, and the effect of temperature on separation was also investigated.
ACKNOWLEDGMENTS
The authors like to acknowledge the National Institute for the Control of Pharmaceutical and Biological Products (People's Republic of China) for providing the standards of ephedrines for this work.