Development of a Dual‐Band Amperometric Detector for Determination of Ascorbic Acid and Glucose

A flow‐through system cell that allows the direct and simultaneous amperometric determination of ascorbic acid and glucose to be performed is described. The electrolytic cell in a thin layer configuration is composed of a gold and a copper‐modified electrode, polarized at −0.10 and 0.50 V, respectively. By using a 1 mol L−1 NaOH solution as carrier electrolyte, amperometric data acquisition was performed simultaneously with a bipotentiostat and the results were analyzed by a multivariate calibration method. Measurements for two commercial pharmaceutical products were carried out without any pretreatment and showed a good correlation with data obtained by using recommended methods. The use of the device to the on‐line quantitative removal of interfering species at the copper electrode is also discussed.