Polarographic and Voltammetric Investigation of Sudan I

The voltammetric and polarographic reduction of the 1-phenylazo-2-naphthol (Sudan I) on a hanging mercury drop electrode (HMDE) and static mercury drop electrode (SMDE) has been studied by using several techniques including square-wave voltammetry (SWV), differential pulse polarography (DPP), direct current polarography (DCP) and cyclic voltammetry (CV) in aqueous and ethanolic Britton-Robinson buffer media. The observed shift of the compound reduction peaks to more negative potentials with increasing pH indicates that hydrogen ions are involved in the electrode reaction. The effect of scan rate and pH on the reduction peaks has been studied. From the polarographic and voltammetric data, electrochemical reduction mechanism of the azo dye has been suggested. The reduction of the azo group to amino group in acidic, neutral and basic media was observed.