DEXTRAN-MODIFIED POLYPROPYLENE HOLLOW FIBERS FOR USE IN CAPILLARY ELECTROPHORESIS

Polypropylene hollow fibers with adsorbed phenyldextran as surface mod ification were shown to give useful and stable columns in capillary el ectrophoresis (CE). Two different sizes of phenyldextran, 40 and 500 K Da, and allyldextran, 150 and 2000 KDa, were examined as physically ad sorbed or chemically immobilized surface modifiers. The use of these s urface modifiers allowed the analysis of proteins such as lysozyme and cytochrome c, which are totally adsorbed on the walls of an unmodifie d polypropylene hollow fiber. Although allyldextran could be crosslink ed, incomplete surface coverage was observed on the polypropylene surf ace. The relative standard deviations in the migration time for the pr oteins lysozyme and cytochrome c on the phenyldextran-modified polypro pylene surface, were 0.9% and 1.4%, respectively, at pH 2.7. The numbe r of theoretical plates for lysozyme and cytochrome c were found to be 200,000-300,000 and 75,000-100,000, respectively. Column-to-column re producibility was < 1% relative standard deviation for relative migrat ion times. The hollow fibers coated with adsorbed phenyldextran also g ave rise to satisfying protein separations even after washing with a s olution of 0.1 M NaOH. (C) 1997 John Wiley & Sons, Inc. 1997.