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 separatio n of large charged molecules such as proteins. Basic and acidic protei ns 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 m m 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 bu ffer medium and also to suppress the electroosmotic flow, even at high er pH values. They were applied to the resolution of protein glycoform s.