Monitoring Electroosmotic Flow by Periodic Photobleaching of a Dilute, Neutral Fluorophore

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• 作者：Kimberley F. Schrum ; Joseph M. Lancaster ; III ; Stephen E. Johnston ; and S. Douglass Gilman
• 刊名：Analytical Chemistry
• 出版年：2000
• 出版时间：September 15, 2000
• 年：2000
• 卷：72
• 期：18
• 页码：4317 - 4321
• 全文大小：59K
• 年卷期：v.72,no.18(September 15, 2000)
• ISSN：1520-6882

文摘

Electroosmotic flow has been monitored in a capillaryusing a method based on periodic photobleaching of aneutral, fluorescent buffer additive. Rhodamine B wasdetermined to be neutral between pH 6.0 and 10.8 andwas added to the running buffer at a concentration of 400nM. Rhodamine B was photobleached by opening ashutter under computer control for 250 ms every 5.00s, to expose the dye to a laser beam and create a photobleached zone. The time was measured for the photobleached zone to migrate 6.13 mm to a downstream laser-induced fluorescence detector, to determine the rate ofelectroosmotic flow in the entire capillary. The flow ratewas sampled every 5.00 s, and the precision of the flowmeasurements was 0.7% or better. Three fluorescentcompounds were separated and detected by capillaryelectrophoresis with laser-induced fluorescence detection,while simultaneously monitoring the electroosmotic flowrate.