Simultaneous voltammetric determination of Brilliant Blue FCF and Tartrazine for food quality control

Voltammetric determination of Tartrazine (Tz) and Brilliant Blue FCF (BB) in their mixture using novel type of carbon black-polyethylene composite electrode (CBPCE) with renewable surface modified by carbon ink (CI) was developed. Electrochemical properties of the tested dyes were investigated in 0.1 mol L⁻¹ Britton-Robinson (BR) buffer by cyclic voltammetry (CV) and linear scan voltammetry (LSV). Simultaneous determination of the dyes is based on the application of supporting electrolytes with different pH: 2.0 for Tz and 10.0 for BB. Under the optimum experimental conditions, linear concentration dependences in the concentration ranges from 0.037 to 1.38 μmol L⁻¹ for Tz and from 0.025 to 2.52 μmol L⁻¹ for BB were obtained by LSV in the first-order derivative mode. Limits of detection (LODs) for Tz and BB were 0.019 and 0.011 μmol L⁻¹, respectively. The modified electrode showed good stability and reproducibility and was successfully applied for the determination of the mixture Tz and BB in a candy and soft drink products.