ELECTROCHEMICAL DETECTOR FOR LIQUID-CHROMATOGRAPHIC DETERMINATION OF CARBOHYDRATES

A highly sensitive and selective electrochemical (LCEC) detector has been developed for the liquid chromatographic (LC) analysis of carbohydrates. This detector consists of copper/copper oxide particles dispersed in a Nafion film that is cast onto the surface of a glassy carbon electrode. The copper is electrochemically deposited into the Nafion by a constant potential method. The response of the detector is based on the catalytic oxidation of various sugars in alkaline solutions at a pH greater than 13. The copper-Nafion-modified electrode exhibits high sensitivity while improving the stability. It allows the convenient quantification of monosaccharides and disaccharides at micromolar concentrations. The response to carbohydrates is assessed with respect to the degree of Nafion coating, copper loading, concentration dependence, time stability, and other variables.