Hydrolytically stable cellulose‐derivative coatings for capillary electrophoresis of peptides, proteins and glycoconjugates

Abstract

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 alkylsilane 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.

Microchannel wall coatings for protein separations by capillary and chip electrophoresis

“…These coatings retained EOF in a manner related to the size of the PEG groups attached to the wall, and thus could be used to create tunable EOF, or step changes in EOF in coupled capillaries [63,64]. Huang et al [65] created cross-linked layers of a copolymer of hydroxypropylcellulose (HPC) and hydroxyethylmethacrylamide (HEMA) by adsorbing fully formed HPC with HEMA monomer on a surface derivatized with 7-oct-1-enyltrimethoxysilane.…”

A very thin coating for capillary zone electrophoresis of proteins based on a tri(ethylene glycol)‐terminated alkyltrichlorosilane

“…Neutral, hydrophilic polymers, either covalently bound or physically adsorbed, create a thick region of very high viscosity that extends beyond the double layer, effectively eliminating EOF [9]. Covalently bound polymers such as polyacrylamide [8,[10][11][12][13][14] and its derivatives [15][16][17][18] are frequently polymerized in situ, but polymer chains can also be bound to the wall fully formed [19][20][21][22]. A wide variety of neutral hydrophilic polymers have also been used as physically adsorbed coatings for protein separations; these include dextran, hydroxyethylcellulose, hydroxypropylmethylcellulose, poly(vinyl alcohol) [23][24][25], polyethylene oxide [26,27], and acrylamide-based polymers such as poly(acrylamide-co-allyl-b-D-glucopyranoside-coallyl glycidyl ether) (epoxy poly(AG-AA)) [28], epoxy-poly (dimethylacrylamide) (EPDMA) [29], and poly(N-hydroxyethylacrylamide) (PHEA, trade name polyDuramide  ) [30].…”

Traitement de surface pour l'électrophorèse capillaire des protéines

“…Huang et al [25,26] ont montré que la formation à la surface du capillaire de couches orientées d'alcényltriméthoxy-silanes générait des films monomoléculaires d'alkylsilane stables en milieu basique, ce qui tend à prouver que les ponts siloxanes sont bien protégés par ce film hydrophobe. Après traitement des capillaires, ainsi modifiés, par du polyacrylamide [25] ou par des copolymères d'hydroxypropylcellulose et de 2-hydroxyéthylméthacrylate réticulés [26], les séparations de protéines réalisées en milieu basique se sont avérées efficaces et reproductibles.…”

“…Après traitement des capillaires, ainsi modifiés, par du polyacrylamide [25] ou par des copolymères d'hydroxypropylcellulose et de 2-hydroxyéthylméthacrylate réticulés [26], les séparations de protéines réalisées en milieu basique se sont avérées efficaces et reproductibles.…”