POSTCHROMATOGRAPHIC ELECTROCHEMICAL DETECTION OF CARBOHYDRATES AT A SILVER-OXIDE ELECTRODE

Silver electrodes, when conditioned at sufficiently positive potential s in the presence of a strong base, can be made to form a silver(I) ox ide or silver(II) oxide surface. In the presence of this oxide surface , carbohydrates may be oxidized and quantitated by means of an electro catalytic scheme. The current which flows to reoxidize the charge-tran sfer mediator (silver oxide) is directly related to concentration of c arbohydrate. Rectilinear response is obtained over at least two decade s of concentration (10(-4) M to 10(-6) M). Design of a prototype elect rochemical cell and studies of optimum cell conditions are discussed. The application of a high-performance liquid chromatography (HPLC) det ector for the separation of some common sugars is illustrated.