Chapter 4 HPLC of Carbohydrates with Cation- and Anion-Exchange Silica and Resin-Based Stationary Phases

Abstract

This chapter provides an overview of different stationary phase matrices and functionalities available for the liquid chromatographic separation of carbohydrates. Interaction of carbohydrates with the stationary phase and ensuing separation mechanisms are also discussed. Automated chromatographic analysis of carbohydrates is most frequently performed on ion-exchange stationary phases. Both cation and anion exchangers may be used as stationary phases for high-performance liquid chromatographic (HPLC) analysis as well as for the preparative isolation of carbohydrates. Because of their higher mechanical stability, which allows the use of higher flow rates, separations on silica-based cation exchangers can be usually achieved more rapidly than on polymer-based stationary phases whose mechanical stability depends strongly on the crosslinking of the polymer. Cation-exchange resins based on poly-styrene/divinylbenzene (PS/DVB) are excellent sorbents for the separation of carbohydrates and are among the most commonly applied stationary phases. Anion-exchange stationary phases are available both on silica and polymers. For the separation of carbohydrates and their derivatives by ion-exchange chromatography on silica-based anion exchangers, mainly two different types of anion exchangers may be distinguished—(1) packings with strong-base anion-exchange groups and (2) packings with weak-base anion-exchange groups.