CAPILLARY ZONE ELECTROPHORESIS SEPARATIONS OF BASIC AND ACIDIC PROTEINS USING POLY(VINYL ALCOHOL) COATINGS IN FUSED-SILICA CAPILLARIES

Poly(vinyl alcohols) (PVA) of a molecular weight of about 50 000 were applied to the modification of fused silica surfaces for the separation of large charged molecules such as proteins. Basic and acidic proteins could be separated in PVA-modified capillaries at highly optimized and analytically suitable performance with regard to efficiency, zone symmetry, and resolution. PVA can be used in the ''dynamic'' mode as mm additive to the buffer medium or as a water-insoluble ''permanent'' coating on the fused silica surfaces which can be achieved by a simple procedure of thermal immobilization. Permanent PVA coatings proved to be stable for series of separations over a wide range of pH of the buffer medium and also to suppress the electroosmotic flow, even at higher pH values. They were applied to the resolution of protein glycoforms.