Simultaneous voltammetric determination of synthetic colorants in food using a cathodically pretreated boron-doped diamond electrode

Differential pulse voltammetry (DPV) and a cathodically pretreated boron-doped diamond (BDD) electrode were used to simultaneously determine two pairs of synthetic food colorants commonly found mixed in food products: tartrazine (TT) and sunset yellow (SY) or brilliant blue (BB) and sunset yellow (SY). In the DPV measurements using the BDD electrode, the reduction peak potentials of TT and SY or BB and SY were separated by about 150 mV. The detection limit values obtained for the simultaneous determination of TT and SY or BB and SY were 62.7 nmol L–1 and 13.1 nmol L–1 or 143 nmol L–1 and 25.6 nmol L–1, respectively. The novel proposed voltammetric method was successfully applied in the simultaneous determination of these synthetic colorants in food products, with results similar to those obtained using a HPLC method at 95% confidence level.