SEC vs. HPLC Variants

In ideal SEC, no interactions between the sample and the support should occur only the pore dimension and the pore size distribution and therefore the volumes related to the porosity and to the interparticle volume can influence the separation. This makes SEC an easy and quick method to handle and to optimize in comparison with other chromatographic techniques such as ion-exchange chromatography or reversed-phase chromatography. Analyses of proteins in SEC are in fact carried out in the isocratic mode and the choice of the mobile phase is only directed to minimize the interactions between the sample and the support surface it does not influence the retention of the analyte when ideal conditions 

Gel filtration may therefore appear to be a very easy protein analysis technique, when no broad elution window or high loadability are required. However, the operation conditions need to be carefully optimized. This is easy in the analysis of synthetic polymers, but the analysis of proteins with complex structures often becomes a difEcult issue. The need for stationary phases that do not interact with the sample, and the choice of a mobile phase that minimizes potential interactions, together with the need to preserve the biological activity of the sample, are frequently not fulfilled and non-ideal conditions may prevail. 

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