Optimized separation of pharmacologically active xanthones from Securidaca inappendiculata by micellar electrokinetic chromatography and microemulsion electrokinetic chromatography

Micellar electrokinetic chromatography (MEKC) has been used for the separation of nine xanthones from Securidaca inappendiculata by using sodium dodecyl sulfate (SDS) micellar system, and the effects of different buffer modifiers including sodium cholate (SC), organic solvent and cyclodextrins (CDs) on the separation selectivity have been extensively studied, based on the systematically optimization of such parameters as pH, concentration of running buffer and SDS concentration. The results indicated that the additions of modifiers could greatly affect the separation selectivity of xanthones, and the migration order of those xanthones depends on their structures and solute-micelle-modifier interactions. As a special variant of electrokinetic chromatography, microemulsion electrokinetic chromatography (MEEKC) has also been utilized for this separation for the comparison with MEKC, showing that MEEKC has better selectivity. (C) 2002 Elsevier Science B.V. All rights reserved.