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Title: Theoretical model of electroosmotic flow for capillary zone electrophoresis

Abstract

A mathematical model of electroosmotic flow in capillary zone electrophoresis has been developed by taking into consideration of the ion-selective properties of silica surfaces. The electroosmotic velocity was experimentally determined, underboth constant voltage and constant current conditions, by using the resistance-monitoring method. A detailed study of electroosmotic flow characteristics in solutions of singly charged, strong electrolytes (NaCl, LiCl, KCl, NaBr, NaI, NaNO{sub 3}, and NaClO{sub 4}), as well as the phosphate buffer system, revealed a linear correlation between the {Zeta} potential and the logarithm of the cation activity. These results suggest that the capillary surface behaves as an ion-selective electrode. Consequently, the {Zeta} potential can be calculated as a function of the composition and pH of the solution with the corresponding modified Nernst equation for ion-selective electrodes. If the viscosity and dielectric constant of the solution are known, the electroosmotic velocity can then be accurately predicted by means of the Helmholtz-Smoluchowski equation. The proposed model has been successfully applied to phosphate buffer solutions in the range of pH from 4 to 10, containing sodium chloride from 5 to 15 mM, resulting in nearly 3% error in the estimation of the electroosmotic velocity. 53 refs., 8 figs., 2 tabs.

Authors:
;  [1]
  1. Michigan State Univ., East Lansing, MI (United States)
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
136269
DOE Contract Number:  
FG02-89ER14056
Resource Type:
Journal Article
Journal Name:
Analytical Chemistry (Washington)
Additional Journal Information:
Journal Volume: 67; Journal Issue: 20; Other Information: PBD: 15 Oct 1995
Country of Publication:
United States
Language:
English
Subject:
40 CHEMISTRY; 42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; ELECTROLYTES; FLUID FLOW; ELECTRIC POTENTIAL; BUFFERS; QUANTITATIVE CHEMICAL ANALYSIS; ELECTROPHORESIS; MATHEMATICAL MODELS; CAPILLARY FLOW; ELECTRIC FIELDS; OSMOSIS; VELOCITY; CALCULATION METHODS; SILICA; SURFACE PROPERTIES

Citation Formats

Tavares, M F.M., and McGuffin, V L. Theoretical model of electroosmotic flow for capillary zone electrophoresis. United States: N. p., 1995. Web. doi:10.1021/ac00116a012.
Tavares, M F.M., & McGuffin, V L. Theoretical model of electroosmotic flow for capillary zone electrophoresis. United States. https://doi.org/10.1021/ac00116a012
Tavares, M F.M., and McGuffin, V L. Sun . "Theoretical model of electroosmotic flow for capillary zone electrophoresis". United States. https://doi.org/10.1021/ac00116a012.
@article{osti_136269,
title = {Theoretical model of electroosmotic flow for capillary zone electrophoresis},
author = {Tavares, M F.M. and McGuffin, V L},
abstractNote = {A mathematical model of electroosmotic flow in capillary zone electrophoresis has been developed by taking into consideration of the ion-selective properties of silica surfaces. The electroosmotic velocity was experimentally determined, underboth constant voltage and constant current conditions, by using the resistance-monitoring method. A detailed study of electroosmotic flow characteristics in solutions of singly charged, strong electrolytes (NaCl, LiCl, KCl, NaBr, NaI, NaNO{sub 3}, and NaClO{sub 4}), as well as the phosphate buffer system, revealed a linear correlation between the {Zeta} potential and the logarithm of the cation activity. These results suggest that the capillary surface behaves as an ion-selective electrode. Consequently, the {Zeta} potential can be calculated as a function of the composition and pH of the solution with the corresponding modified Nernst equation for ion-selective electrodes. If the viscosity and dielectric constant of the solution are known, the electroosmotic velocity can then be accurately predicted by means of the Helmholtz-Smoluchowski equation. The proposed model has been successfully applied to phosphate buffer solutions in the range of pH from 4 to 10, containing sodium chloride from 5 to 15 mM, resulting in nearly 3% error in the estimation of the electroosmotic velocity. 53 refs., 8 figs., 2 tabs.},
doi = {10.1021/ac00116a012},
url = {https://www.osti.gov/biblio/136269}, journal = {Analytical Chemistry (Washington)},
number = 20,
volume = 67,
place = {United States},
year = {1995},
month = {10}
}