Bismuth Film Electrodes for Adsorptive Stripping Voltammetric Determination of Sunset Yellow FCF in Soft Drinks

The bismuth film electrode was used to record well-developed voltammograms of azo food coloring Sunset Yellow FCF (SY). The employed Bi(III)/HClO4 plating solutions produced very adhesive and mechanically stable films that were applied in both stationary and flow conditions. The influence of the dimensions of the glassy carbon support, plating solution concentration and potential was discussed. The sensitivity of SWV was sufficient to obtain a linear calibration curve for low concentration levels of SY (below 0.1 mg/L; LOD=1 µg/L, linear range 4.4–87 µg/L). The measurements in a flow system were considered as a tool for the determination of relatively high concentrations (>1 mg/L; LOD=300 µg/L, linear range 300–8800 µg/L) of SY.