A mathematical model for hydrodynamic and size exclusion chromatography ofpolymers on porous particles

When packed columns filled with porous particles are used for the separatio n of macromolecules, either size exclusion chromatography (SEC), hydrodynam ic chromatography (HDC), or a combination of both determine the macromolecu le retention mechanism. This paper develops a simple mathematical model to describe a molecular weight calibration graph, which includes both HDC and SEC, There is a transition between the HDC calibration region at higher mol ecular weights to an SEC region at lower molecular weights. The degree to w hich SEC and HDC are mixed depends on the particle diameter, the relative s ize of the pores, and the macromolecule size. In addition, using fractal co nsiderations, the fractal character of the apparent selectivity between two adjacent peaks on the chromatogram is shown. This model constitutes an att ractive tool to enhance the expansion of these two chromatographic techniqu es for the separation of biological or synthetical macromolecules.