Separation of Enantiomers of Cathinones by Capillary Electrophoresis Using Cyclodextrins as Chiral Selectors

Abstract

This paper deals with a chiral separation of six cathinones using three commercially available cyclodextrins as additives to the background electrolyte consisting of a phosphate buffer at pH 2.5. The best resolution values were obtained by the addition of sulfated β-cyclodextrin at 5 mmol L^–1 concentration in the background electrolyte. Four complete chiral separations of racemic cathinones were achieved. Other two racemic cathinones were successfully enantioseparated by addition of carboxymethylated β-cyclodextrin at 15 mmol L^–1 concentration in the background electrolyte. For one of the cathinones analyzed, the apparent stability constants of β-cyclodextrin and the average apparent stability constants of carboxy­methylated β-cyclodextrin were calculated and it was found that a more stable complex is formed for carboxy­methylated β-cyclodextrin.