Collect. Czech. Chem. Commun. 1987, 52, 867-877

The polarographic and voltammetric determination of congo red

Jiří Barek, Barbara Tietzová and Jiří Zima

Department of Analytical Chemistry, Faculty of Natural Sciences, Charles University, 128 40 Prague 2


The polarographic reduction of the bisazodye congo red has been studied, a mechanism was proposed for this process and optimal conditions were found for determination of this substance by TAST polarography and differential pulse polarography at a dropping mercury electrode and using fast scan differential pulse voltammetry and voltammetry with linearly increasing voltage at a hanging mercury drop electrode. The detection limit for the latter two techniques is about 10-8 mol l-1; a further decrease in the value can be attained by prior accumulation of the determined substance by adsorption on the surface of the working electrode.