SIZE EXCLUSION CHROMATOGRAPHY OF DEXTRANS IN DMSO AS ELUENT

Abstract

The elution conditions for an appropriate size exclusion chromatographic (SEC) characterization of dextrans were checked on a divinylbenzene grafted glucose column. Different eluents were tested. With neutral aqueous eluents, the dextrans were irreversibly adsorbed. In KOH, the separation was rather good but we could note some elution volume shifts when the KOH concentration was changed, and the solute was rapidly degraded by hydrolysis. The mixtures of DMSO/H₂O did not enable the dextrans to completely dissolve and large aggregates were present in the solution. In pure DMSO, even at 70°C, the polysaccharides were only partially eluted. The addition of a small quantity of salt to DMSO allowed total recovery of the samples. In DMSO + salt, the elution volumes shifted when we changed the nature of the salt but these differences were independent of the salt concentration. The secondary interactions were not relevant enough so that we could consider that the dextrans were primarily eluted by means of size exclusion.

Acknowledgments