Estimation of the Binding Constant of Sugar Alcohol to Sodium Ion by Using Its Apparent Distribution Coefficients to Cation-exchange Resins with Different Cross-linkages

抄録

The apparent distribution coefficients, K_app, of some sugar alcohols to cation-exchange resins in the sodium-ion form and with divinylbenzene (DVB) contents of 2, 4, 6, and 8% were measured at 25ºC. Assuming that the binding constant, B, of ribitol to sodium ion was zero, the swelling pressures, Π, of the resins in sodium-ion form with DVB contents of 2, 4, 6, and 8％ were estimated to be 3.2, 9.4, 12.3, and 25.7 MPa, respectively. From these Π values and K_app values, the B values of each sugar alcohol were calculated. Because the B value is independent of the degree of cross-linking of the resin, the B values were obtained from the K_app for resins with different DVB contents and were averaged. Erythritol and sorbitol had almost zero binding affinity to sodium ion. Among the tested sugar alcohols, the B values were in the order of xylitol > d-arabitol, l-arabitol > mannitol.