HYDROLYTICALLY STABLE CELLULOSE-DERIVATIVE COATINGS FOR CAPILLARY ELECTROPHORESIS OF PEPTIDES, PROTEINS AND GLYCOCONJUGATES

A method for the preparation of versatile, hydrolytically stable coatings of fused silica capillaries is described. First, the HNO3-pretreated silica surface is reacted with 7-oct-1-enyltrimethoxysilane to form a stable self-assembled alkyl-silane monolayer. Secondly, the copolymer of hydroxypropylcellulose and 2-hydroxyethyl methacrylate is statically coated onto a hydrophobized wall. This allows the formation of a highly crosslinked copolymer layer which is tightly bound to the wall surface. Hydrolytical stability in the pH range of 2-10 for several weeks has been demonstrated. The coating generates a low electroosmotic flow at alkaline pH, which can be easily masked by using special buffers. The versatility of this column technology is documented by separations of peptides, glycoproteins and derivatized oligosaccharides.