Purposeful regulation of electroosmotic flow in chemically modified fused-silica capillaries for optimization of capillary electrophoresis of proteins

Chemical modification of the capillary inner surface by means of grafting poly(sulfopropylmethacrylate) has been suggested in order to stabilize the electroosmotic flow (EOF). It is shown that such modified stable coatings provide independence of EOF rate from pH as well as the absence of hysteresis typical for untreated silica capillaries. By the example of serum protein analysis, it has been demonstrated that poly(sulfopropylmethacrylate) coating also provides increased resolution of protein fractions and eliminates the necessity of capillary rinse with alkali solution before and after analysis.