High-Performance Ion Exchange Chromatography HPIEC of Mono- and Oligosaccharides

6 High-Performance Ion Exchange Chromatography (HPIEC) of Mono- and Oligosaccharides 

At strong alkaline conditions mono- and oligosaccharides are weak anions. So it is possible to separate them on alkaline-resistant HPLC columns. Whereas spectrophotometric monitoring is not possible, pulsed amperometric detection allows sensitive identification in the nanomolar range. 

In the literature, isocratic solvent systems are found for monosaccharides, and gradient systems are described for oligosaccharides. Table 3.4 gives some gradient systems for carbohydrate separation Table 3.5 illustrates programs for pulsed amperometric detectors. 

The strong alkaline solvents need some special efforts concerning materials. Capillaries and fittings should be of PEEK. The injection valve must be designated to be alkali resistant (e.g., Tefzel rotors of Rheodyne valves). Storage bottles for mobile solvents have to be of plastics and should be supplemented with a tube filled with caustic soda pellets. 

There is no need to degas solvents, but filtration using 0.45-pm Teflon filters is indispensable. 

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