An Analysis of the Concentration Effects on Elution Volumes by Using the Preferential Solvation Parameter in Two SEC Packings
✍ Scribed by Rosa García-Lopera; Clara M. Gómez; Concepción Abad; Agustín Campos
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 160 KB
- Volume
- 203
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
Size exclusion chromatography (SEC) elution behavior of different solvent/polymer systems has been analyzed from chromatographic, thermodynamic, and hydrodynamic points of view in two organic column packings based on polystyrene/divinylbenzene (PS/DVB) copolymer, μ‐styragel and TSK‐Gel H~HR~. Although both packings present similar chromatographic properties, some differences arise when eluting the same systems. The values of the adsorption distribution coefficients, K~p~, have been correlated with the preferential solvation coefficient, λ (see Figure), for both packings, showing that those systems with lower and negative λ values (denoting higher preferential solvation of the polymer by the gel packing) are those with K~p~ > 1. In addition, the main goal has been to make use of the λ values to adequately interpret the dependence of the elution volumes on injected polymer concentration. In this regard, the experimental concentration effects have been completely explained by taking into account not only the conventional hydrodynamic factors but also thermodynamic aspects such as the preferential solvation phenomenon.
Plot of the preferential solvation coefficient, λ, as a function of the volume fraction of polymer (2), ϕ~2~, at three hydrodynamic volumes, V~h~ = 10^6^ (○ •); 10^7^ (□ ▪), and 10^8^ (▵ ▴) mL · mol^−1^ for the system THF/PBD/PS (μ‐styragel: empty symbols; TSK‐Gel H~HR~ (solid symbols).
magnified imagePlot of the preferential solvation coefficient, λ, as a function of the volume fraction of polymer (2), ϕ~2~, at three hydrodynamic volumes, V~h~ = 10^6^ (○ •); 10^7^ (□ ▪), and 10^8^ (▵ ▴) mL · mol^−1^ for the system THF/PBD/PS (μ‐styragel: empty symbols; TSK‐Gel H~HR~ (solid symbols).