SOLUTION PROPERTIES OF POLYELECTROLYTES .7. NONIDEAL MECHANISMS IN SIZE-EXCLUSION CHROMATOGRAPHY OF SYNTHETIC POLYIONS, PEPTIDES AND PROTEINS

Chromatographic data for sodium polystyrene sulphonate were obtained on both silica- and polymer-based size-exclusion supports using mobile phases of various pH and ionic strength. Deviations of the elution volume were observed towards both lower and higher values relative to the reference calibration graph obtained with uncharged standards. An empirical correlation is proposed in order to account for all the secondary effects observed. The general applicability of this correlation was further tested for chromatographic data obtained for a series of peptides and proteins on a silica-based support under very different eluent conditions. Deviations from ideal elution behaviour such as ion-exclusion and hydrophobic effects were analysed in the light of this approach.