ISSN:
1612-1112
Keywords:
Gel-permeation
;
Gel solvation
;
Mobile phase composition
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary The paper discusses the effect of the composition of a mixed eluent inside the gel and in the mobile phase on the separation mechanism in gel chromatography. An increase in the concentration of one of the eluent components can result from the preferential solvation of the macromolecules forming the gel matrix. Different composition of the mobile and quasistationary (gel) phases can significantly influence the distribution co-efficient of the solute and make the thermodynamic partition more important within the separation process of gel chromatography. In analogy with liquid-liquid chromatography it is suggested that the contribution of thermodynamic partition can be determined with help of the activity coefficients of the solute and the composition of both phases. Experimental results for dextran and polystyrene gels in binary mixtures show the effect of the gel’s chemical structure, its polarity and degree of crosslinking on its preferential solvation. Quantitative evaluation of the preferential solvation makes it possible to determine the internal solvent composition in the column. The analogy between the description of both the preferential solvation of the gel and the surface adsorption based on the Gibbs adsorption isotherm is also pointed out.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02314761
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