ANALYSIS OF SEPARATION EFFICIENCY IN CAPILLARY ELECTROPHORESIS WITH DIRECT CONTROL OF ELECTROOSMOSIS BY USING AN EXTERNAL ELECTRIC-FIELD

Direct control of electroosmosis in capillary electrophoresis with the application of an external electric field is demonstrated by the UV marker method. When the zeta potential at the capillary/aqueous solution interface is small, the capacitor model qualitatively and quantitatively predicts the effectiveness of the external electric field for controlling electroosmosis at different electrolyte concentrations and capillary dimensions. To investigate the separation efficiency of capillary electrophoresis with the direct control of electroosmosis, frontal analysis of dimethyl sulfoxide as a UV marker are examined. There is no measurable additional band broadening induced by the application of an external electric field.