Optimization of the separation of flavonoids by micellar electrokinetic capillary chromatography: Effect of organic solvents

A group of flavonoids of special interest to wine qualify were separated by micellar electrokinetic chromatography (MEKC) with diode array detection. Their separation was optimized as a function of the buffer concentration an d pH, the concentration of sodium dodecyl sulfate (SDS) and the applied vol tage. Selectivity and resolution of the solutes were increased by adding or ganic solvents to the separation buffer, the best results being obtained at lower concentrations. An optimized buffer with 5% methanol provided optimu m separation with regard to efficiency resolution and migration time. The o ptimized method was applied to the determination of these compounds in wine samples.