BAND BROADENING ARISING FROM STEPWISE ALTERATIONS IN MOBILE-PHASE COMPOSITION IN MICELLAR ELECTROKINETIC CHROMATOGRAPHY

Gradient elution in micellar electrokinetic chromatography has been pr oposed as a technique for extending the elution range and adjusting re tention factors for optimum values. It is shown that this approach in practice has not only to be evaluated for adjustment of retention fact ors but also for the reduced efficiency of the chromatographic system arising from alterations in the separation buffer during the run. Step wise gradient elution, feasible with commercial instrumentation, resul ts in marked peak broadening attributable to effects of the border zon e passing the solute zone.