Elution Behavior of Carbohydrates for Core-Shell Ion-Exchange Resin St-70 with Different Number of Methylene Group in the Porous Shell and a Constant Cross-Linking Degree of 55%

Understanding the relationship between the molecular structure ion-exchange resins and the elution of carbohydrates is important for high-performance liquid chromatography (HPLC). From a novel resin development perspective, we focused on the effect of the number of methylene groups in the functional chain of the porous polymer shell. Herien, core-shell ion-exchange resins with a monomer weight ratio of 30:70 (denoted as St-70) were synthesized with a constant cross-linking degree of 55%. The number of methylene groups in the functional chain of the porous polymer shell was varied from two to six. The effect of the number of methylene groups on the carbohydrate separation performance was examined under strong alkaline conditions. A mixture of inositol, glucose, fructose, and sucrose was separated using a 0.10 or 0.15 mol/L NaOH eluent at flow rates of 0.3–0.7 mL/min. The retention times were compared for St-70 variants with different numbers of methylene groups in the porous layer. Increasing the number of methylene groups tended to increase the retention times of each carbohydrate under all conditions. The theoretical plate numbers of carbohydrates decreased and then increased as the number of methylene groups increased from two to six. The results suggest that the St-70 core-shell ion-exchange resins are highly efficient for carbohydrate analysis. Their suitability for strongly alkaline conditions allows their effective use in electrochemical detection.