Jump to main content
Jump to site search

Issue 8, 2001
Previous Article Next Article

On-line monitoring of electroosmotic flow for capillary electrophoretic separations

Author affiliations


A recently developed technique for monitoring electroosmotic flow (EOF) in capillary electrophoresis by periodic photobleaching of a neutral fluorophore added to the running buffer has been further characterized and optimized and then applied to monitoring EOF during a typical capillary electrophoresis separation. The concentration of neutral fluorophore (rhodamine B) added to the running buffer for monitoring EOF has been decreased by one order of magnitude. The rate at which EOF can be measured has been increased from 0.2 to 1.0 Hz by decreasing the distance between the bleaching beam and the laser-induced fluorescence detector from 6.13 to 0.635 mm. The precision of the measured EOF ranges from 0.2 to 1.8%. Under typical experimental conditions, the dynamic range for flow measurements is 0.066 to 0.73 cm s−1. Experimental factors affecting precision, signal-to-noise (S/N) ratio and dynamic range for EOF monitoring have been examined. This technique has been applied to measure EOF during a separation of phenolic acids with analyte detection by UV/VIS absorbance. The EOF monitoring method has been shown not to interfere with UV/VIS absorbance detection of analytes.

Back to tab navigation

Article information

12 Apr 2001
20 Jun 2001
First published
23 Jul 2001

Analyst, 2001,126, 1240-1247
Article type

On-line monitoring of electroosmotic flow for capillary electrophoretic separations

J. L. Pittman, K. F. Schrum and S. D. Gilman, Analyst, 2001, 126, 1240
DOI: 10.1039/B103316F

Social activity

Search articles by author