Effects of analyte velocity modulation on the electroosmotic flow in capillary electrophoresis.
Modulation of the electroosmotic flow in capillary zone electrophoresis by modulation of the driving voltage gives rise to a flow profile that changes between laminar and flat profiles. The changing flow profile induces a radial movement of sample species to and from the capillary surface. The induced sample concentration gradient can be monitored by carefully probing the capillary surface. The resulting signal is a derivative of the normal-shaped peak. Derivative-shaped peaks can be observed with cations, but not with anions. Anions are unable to approach the double-layer region and therefore are unaffected by the modulation process.
Demana
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University of Michigan, Department of Chemistry, Ann Arbor 48109-1055.
Guhathakurta
U
U
Morris
M D
MD
D000097:Acetonitriles / Q000032:analysis; D004121:Dimethyl Sulfoxide / Q000032:analysis; D004586:Electrophoresis / Q000379:methods*; D008433:Mathematics; D012235:Rhodamines / Q000032:analysis; D013050:Spectrometry, Fluorescence
D000097:Acetonitriles; D012235:Rhodamines; C026188:rhodamine 6G; D004121:Dimethyl Sulfoxide; C032159:acetonitrile