Chromatographic separation of mannitol from mixtures of other carbohydrates in aqueous solutions

Abstract

The isolation of mannitol from natural sources, e.g. from plant extracts or broths, requires considerable time and effort. The separation of mannitol from aqueous solutions containing also glucose, fructose, and sucrose was tested using discontinuous preparative anion- and cation-exchange chromatography. The suitability of the application in the separation of carbohydrates and especially mannitol was tested under various conditions and using three different types of ion-exchangers. The effect of sorbent regeneration and modification on the separation was also examined using different concentrations and volumes of chemical agents. The fractions collected after the discontinuous chromatography were analysed on the content of mannitol by the high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) method. The successful isolation of pure mannitol fraction, using water as a mobile phase and a combination of sodium chloride and hydroxide for sorbent regeneration, was achieved only on anion-exchange chromatography.