THEORY OF GEL-PERMEATION CHROMATOGRAPHY - MECHANISM OF SEPARATION AND THE INFLUENCE OF POLYMER-SORBENT INTERACTION

The displacement of hydrodynamic volume universal calibration curves to high retention volumes for some polymer-solvent systems in gel permeation chromatography is explained in terms of a network-limited separation consisting of a steric exclusion mechanism and a second mechanism resulting from polymer-sorbent interaction. This treatment is consistent with a thermodynamic interpretation of gel permeation chromatography in which the distribution coefficient (≥ 1.0) for polymer-sorbent interaction is determined by an enthalpy change for polymer partition or polymer adsorption in the porous packing. Experimental data obtained with crosslinked polystyrene gels and inorganic packings may be represented by the network-limited treatment. Separations in which the distribution coefficient for polymer-sorbent interaction is less, than unity correspond to partial exclusion by polymer incompatibility with the sorbent. © 1979, Walter de Gruyter. All rights reserved.