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

The separation of nutritionally significant saccharides in fruit juice s was investigated by high-performance anion-exchange chromatography w ith pulsed amperometric detection (HPAEC-PAD). The effect of sodium hy droxide concentration in the mobile phase on the retention and selecti vity was investigated on three different pellicular anion-exchange col umns (all from Dionex). The sugar alcohol sorbitol and the sugars gluc ose, fructose, and sucrose were well resolved in less then 10 minutes on the CarboPac PA 100 column by using simple isocratic elution with 1 50 mM sodium hydroxide solution, without column regeneration between r uns. Under these conditions the relative standard deviations of the re tention times were better than 0.98%. HPAEC-PAD was successfully appli ed to the determination of the major sugars in a fruit concentrate and in several varieties of commercial fruit juices by an internal standa rd method without any sample pretreatment.