HIGH-PERFORMANCE ANION-EXCHANGE CHROMATOGRAPHY WITH PULSED AMPEROMETRIC DETECTION OF NUTRITIONALLY SIGNIFICANT CARBOHYDRATES

The separation of nutritionally significant saccharides in fruit juices was investigated by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The effect of sodium hydroxide concentration in the mobile phase on the retention and selectivity was investigated on three different pellicular anion-exchange columns (all from Dionex). The sugar alcohol sorbitol and the sugars glucose, fructose, and sucrose were well resolved in less then 10 minutes on the CarboPac PA 100 column by using simple isocratic elution with 150 mM sodium hydroxide solution, without column regeneration between runs. Under these conditions the relative standard deviations of the retention times were better than 0.98%. HPAEC-PAD was successfully applied to the determination of the major sugars in a fruit concentrate and in several varieties of commercial fruit juices by an internal standard method without any sample pretreatment.