Elution Behavior of Carbohydrates for Core-Shell Ion-Exchange Resin St-50 with Different Degrees of Cross-Linking in the Porous Shell

Reducing the retention time in carbohydrate analysis is crucial to the development of resins for application in high-performance liquid chromatography (HPLC). In order to solve this problem a new core-shell ion-exchange resin with a thin shell layer consisting of an ion-exchanging porous shell layer on a hard polymer core was prepared for use in HPLC. The effect of the degree of cross-linking (10–55%) in the shell, wherein the core/shell monomer weight ratio was 50:50 (St-50), on the retention time and theoretical plate number (N) of the separated carbohydrates was examined. A mixture of inositol, glucose, fructose, and sucrose was separated under alkaline conditions (0.10 mol/L NaOH) at flow rates of 0.3–0.7 mL/min using St-50, which exhibited a degree of cross-linking of 40 and 55%. The retention time of carbohydrates was found to be related to the degree of cross-linking in the porous layer. The values of N for glucose, fructose, and sucrose were dependent on the degree of cross-linking at all flow rates when a 0.10 mol/L NaOH eluent was used.