ADSORPTIVE SEPARATION OF OLIGOSACCHARIDES: INFLUENCE OF CROSSLINKING OF CATION EXCHANGE RESINS

摘要

The influence of crosslinking on the sorption properties of poly(styrene-co-divinylbenzene) (PS-DVB) strong acid ion exchanger in K~+ or Ca~(2+) form was studied. Isotherms of sugars were determined for resin containing 2, 4 and 8% DVB. Sorption was strongly influenced by the degree of crosslinking. At increasing crosslinking the amount of sorption by (non-selective) distribution decreases and complexation is the dominant sorption mechanism. Resin with 2% DVB was hardly selective, but resin with 8% DVB was very selective. A selectivity of 7.0 for fructose/sucrose and Ca~(2+) loaded resin was obtained due to a combination of size exclusion and complexation. However, sorption capacity decreased with increasing crosslinking. Chromatograms of fructo- and galactooligo-saccharides (OS) showed that the separation of the monosaccharides from the OS was best for 8% DVB but the fractionation of the OS was best for 2% DVB.