SEPARATION OF HYDROXYLATED AND METHOXYLATED FLAVONOIDS BY MICELLAR ELECTROKINETIC CAPILLARY CHROMATOGRAPHY - DETERMINATION OF ANALYTE PARTITION-COEFFICIENTS BETWEEN AQUEOUS AND SODIUM DODECYL-SULFATE MICELLAR PHASES

The capacity factors (k(corr)') of ionized flavonoids have been determ ined after correction from the influence of buffer pH and their depend ence versus sodium dodecyl sulfate (SDS) micelle concentration was fou nd to be linear in micellar electrokinetic capillary chromatography (M EKC). The partition coefficients between aqueous and SDS micellar phas es of several flavonoids have been deduced from these linear curves an d their values interpreted from the structural features of these compo unds. Additionally, the critical micelle concentration (CMC) value of SDS surfactant was determined. Finally, a mixture of seven hydroxylate d and methoxylated flavonoids has been resolved by MEKC using 20 mM Na 2B4O7-25 mM SDS, 20% CH3OH electrolyte (pH 8). (C) 1997 Elsevier Scien ce B.V.