Simultaneous Estimation of the Binding Constant of Saccharide to Sodium Ion and the Swelling Pressure of Cation-exchange Resin

Abstract

The apparent distribution coefficients, K_app, of some mono-, di- and trisaccharides onto cation-exchange resins in the sodium-ion form and having the divinylbenzene (DVB) contents of 4, 6 and 8% were measured at 25°C. A method for simultaneously estimating the swelling pressures of the resins and the binding constants, B, of the saccharides to the sodium ion was proposed. By applying the method to the K_app values of mono- and disaccharides, the swelling pressures of the resins having the DVB contents of 4, 6 and 8% were estimated to be 18.9, 30.8 and 37.8 MPa, respectively, and the B values of the mono- and disaccharides were also estimated simultaneously. The B values of the trisaccharides were calculated using the estimated swelling pressures. The B values ranged from 0.24 to 2.2 L/mol. The tri-, di- and monosaccharides had higher B values in this order. There was a tendency that the solute, which can form a tridentate complex with the sodium ion, contains high numbers of axial-equatorial and equatorial-equatorial complexing hydroxyl groups.