Abstract: The electrode was prepared by casting 50 mM Co(NO3)2 solution on a clean glassy C surface, drying the electrode at 60°C for 30 min and rinsing with water. X-ray photoelectron spectroscopy measurements indicated that Co(IV) was present on the electrode surface during the cyclic voltammetry of mono-, di- and tri-saccharides in alkaline medium. The electrodes were used as an amperometric detector for these carbohydrates after anion-exchange LC on a Carbopac PA1 column (25 cm x 4 mm), operated at 22°C, with 0.20 M NaOH as the mobile phase (1.0 mL min-1). The operating potential was 0.50 V vs. Ag - AgCl. The detectors were also used in a flow injection system for the detection of glucose in a 0.20 M NaOH carrier stream. The response was rectilinear over a dynamic range from 0.5 µM to 0.5 mM glucose. The average peak current was 2.23 µA and coefficient of variation (n = 14) was 1.6%. A cobalt-based glassy carbon (Co/GC) chemical modified electrode (CME) is described for use as an amperometric detector in the flow anal. of mono-, di- and trisaccharides. The preparation of the electrode is very easy and rapid. As with copper- and nickel-based glassy carbon electrodes, the Co/GC CME allows the electrocatalytic oxidation of scarcely electroactive compounds without recourse to pulsed waveform potentials. Hence, constant-potential amperometric detection is feasible and it has been applied successfully to reducing and nonreducing sugars. The chemical nature of cobalt species on glassy carbon was investigated using XPS and the results indicate that a Co(III) oxide hydroxide is present on the glassy carbon surface. However, electrochemical detection in an alkaline mobile phase of aliph. organic compounds seems to take place through mediation of Co(IV) species produced from the oxidation of Co(III) during anodic polarization. Carbohydrates and related polyhydroxy compounds were determined at the micromolar level with an operating potential of 0.50 V vs. Ag/AgCl after anion-exchange chromatography separation The detector responds linearly to an increase in glucose concentration with a linear dynamic range that extends over three orders of magnitude (0.5 µM-0.5 mM).