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An approach to ideal separation media for (electro)chromatography
S Hjertén1, A Végvári, T Srichaiyo
1Department of Biochemistry, Uppsala University, Sweden.
Journal of Capillary Electrophoresis
|May 18, 1999
Summary
Homogeneous continuous beds, like gels, offer ideal chromatographic separation by minimizing zone spreading. This method, electrochromatography in gels, achieves high resolution by controlling electroendosmotic flow and analyte interactions.
Area of Science:
- Chromatography
- Separation Science
- Analytical Chemistry
Background:
- Packed chromatographic beds suffer from zone spreading due to Eddy diffusion and long analyte residence times in the mobile phase.
- Macroscopically homogeneous separation media, such as gels, theoretically offer higher resolution by reducing these factors.
- Homogeneous continuous beds (monoliths) present a promising alternative for improved chromatographic performance.
Purpose of the Study:
- To investigate the potential of homogeneous continuous beds, specifically gels, as an ideal chromatographic medium.
- To evaluate the role of electroendosmosis in achieving high resolution in gel-based chromatography.
- To explore methods for synthesizing functionalized gels that facilitate efficient electroendosmotic flow and analyte separation.
Main Methods:
- Experimental verification using frontal analysis with a neutral marker (acetone) to assess zone distortion.
- Theoretical analysis of electroendosmotic velocity and its dependence on gel pore size and double-layer thickness.
- Synthesis of a functionalized agarose gel incorporating phenylboronate and acrylic acid groups to generate electroendosmotic flow and enable dual separation mechanisms.
Main Results:
- Electrochromatography in homogeneous gels demonstrated negligible Eddy diffusion and nonspecific adsorption, leading to high resolution.
- Acetone frontal analysis showed minimal distortion, indicating near-perfect plug flow driven by electroendosmosis.
- A synthesized functionalized gel exhibited dual separation capabilities for cis-vicinal diols and aromatic compounds, driven by boronate complexation and aromatic adsorption, respectively.
Conclusions:
- Homogeneous continuous beds, particularly gels, represent a highly efficient chromatographic method with the potential for ideal separation.
- Controlling electroendosmotic flow and optimizing analyte-bed interactions are crucial for maximizing the benefits of these systems.
- The developed universal method for synthesizing functionalized gels provides a versatile platform for advanced chromatographic separations.