Dispersion studies of capillary electrophoresis with direct control of

Anal. Chem. 1093, 65,568-571

588

Dispersion Studies of Capillary Electrophoresis with Direct Control of Electroosmosis Chin-Tiao Wu, Tung-Liane Huang, and Cheng S. Lee' Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County Campus, Baltimore, Maryland 21228

Cary J. Miller Department of Chemistry and Biochemistry, University of Maryland at College Park, College Park, Maryland 20742

The { potential and the electroosmotlc flow In caplllary

ekctrophorerk can be directly controlled by uslng a radlal electrlc potentlal gradlent across the caplllary wall. Flow profller and dlsperrlon In the caplWary wlth the direct control of electroormosls are studkd. The values of total spatlal varlance measured from the expwhent are In good agrement wlth the predlctlons based on only molecular dMudon. There Is no measurable addltlonal dlspelulon and band broadenlng Induced by the dlrect control of electroomosls. A dc short clrcult phenomenon at the caplllary/oolutlon Interface Is proposed for explalnlng our experlmental obrervatlons.

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