EFFECTS OF ALKYLAMINES ON ELECTROOSMOTIC FLOW AND PROTEIN MIGRATION BEHAVIOR IN CAPILLARY ELECTROPHORESIS

This paper reports the use of four closely related alkylamines as running electrolyte additives in capillary electrophoresis that permit the control of electroosmotic flow and protein migration behaviour in uncoated capillaries. At pH 2.5 the direction of the electroosmotic flow was anodic with all additives and at constant ionic strength its magnitude increased with increasing alkylamine concentration. The observations are in qualitative agreement with a previous reported theoretical model that correlates the electroosmotic mobility with the charge density in the Stern region of the electric double layer, arising from the adsorption of the additive, and the charge density at the capillary wall due to dissociation of silanols.