Cellulose modified polypropylene hollow fibers for capillary electrophoresis

A new method for the modification of polypropylene hollow-fiber columns for capillary electrophoresis is reported. Chlorination was first used to activate the capillary inner surface. This was followed by treating the column with an alkaline solution containing polyhydroxypropylcellulose. A protein mixture was used to examine the modified column inner surface, and a hydrophilic polymer layer was confirmed to be chemically bonded to the surface by carefully studying the electrophoretic performance of columns at each step of their preparation. The resultant columns had zero electroosmotic flow, indicating that charged groups on the inner surface had been efficiently masked. Theoretical plate numbers as high as 7.0 × 105 plates m−1 for basic protein separations were obtained on 85-μm i.d. polypropylene hollow-fiber columns.