HPLC ANALYSIS OF CARBOHYDRATES IN WINES AND INSTANT COFFEES USING ANION-EXCHANGE CHROMATOGRAPHY COUPLED TO PULSED AMPEROMETRIC DETECTION

Carbohydrates (arabinose, fructose, fucose, galactose, glucose, mannos e, rhamnose, ribose, sucrose, xylose, and the alditol mannitol) have b een analyzed in wines and instant coffees, using anion exchange chroma tography coupled to pulsed amperometric detection. Good separation and resolution of the 11 compounds were obtained using just nanopure wate r as eluent, although rinsing the column with 0.2 M NaOH was necessary to avoid gradual decline in column resolution. Coffee solution, red w ines, and rose wines needed a cleanup process by solid-phase extractio n on C-18 cartridges. Arabinose, galactose, glucose, xylose, mannose, fructose, and ribose were detected and quantified in red wines using m elezitose as internal standard. In the case of the coffee samples mann itol, fucose, arabinose, rhamnose, galactose, glucose, sucrose, mannos e, and fructose were quantified and differences between unadulterated and adulterated coffees could be detected.