Free Solution Capillary Electrophoretic Separation of Basic Proteins and Drugs Using Cationic Polymer Coated Capillaries

Abstract
A simple capillary coating which exhibits reversed (anodic) electroosmotic flow (EOF) has been developed for the separation of cationic compounds by free solution capillary electrophoresis. Poly(2-aminoethyl methacrylate hydrochloride) (PAEM) was chemically bound onto the fused-silica capillary inner wall. Capillaries modified by this method exhibit an essentially pH-independent EOF in the pH range from 3 to 5.5, and have been applied to the improved separation of basic proteins and drugs (e.g., beta-adrenergic blocking drugs). High efficiency and precise migration (relative standard deviation was less than 1%) were observed.