Xl. Ren et al., HYDROPHILIC POLYMER-MODIFIED POLYPROPYLENE HOLLOW FIBERS WITH CONTROLLABLE ELECTROOSMOTIC FLOW FOR CAPILLARY ELECTROPHORESIS, The Journal of microcolumn separations, 8(8), 1996, pp. 535-540
Fused-silica capillaries often lack long-term stability and control of
electroosmotic flow in capillary electrophoresis owing to the reactiv
ity of the bulk silica structure in aqueous solutions of high or low p
H. Polypropylene hollow fibers, an alternative to fused silica, have b
een chemically modified to control the electroosmotic Bow. Ionic funct
ional groups were used to vary or change the direction of electroosmot
ic flow. Polymeric surface coatings containing sulfonic acid and quate
rnary amine functionalities, and a novel polyphosphazene were bonded t
o the polypropylene surface and evaluated for electrophoresis and elec
troosmotic flow control. Varying magnitudes of electroosmotic flow wer
e obtained with different concentrations or mixtures of these coatings
. The resultant columns were successfully used for small-molecule sepa
rations, such as substituted pyridines and DNA bases. (C) 1997 John Wi
ley & Sons, Inc.