Rapid and straightforward electrochemical approach for the determination of the toxic food azo dye tartrazine using sensors based on silver solid amalgam

Abstract

The research paper reports for the first time the investigation of the electrochemical reduction of the synthetic food azo dye tartrazine (TZ) on three different types of silver solid amalgam electrodes (AgSAEs), in particular, the polished one (p-AgSAE), covered by mercury film (f-AgSAE) or by mercury meniscus (m-AgSAE), and the comparison with dropping mercury electrode. The highest reduction peak of TZ on AgSEAs was obtained in the Britton-Robinson buffer (pH 3.4). It was shown that the accumulation step can considerably increase the peak height of TZ reduction. Two adsorptive stripping voltammetric techniques, the linear sweep (LS-AdSV) and the differential pulse (DP-AdSV), were used to develop the simple, rapid, and sensitive methods for the determination of TZ based on its reduction on the working AgSAE. The results showed that all three AgSAEs can be applied for electroanalysis of TZ, however, the best limit of detection (0.078 μmol L−1) and the limit of quantification (0.24 μmol L−1) were obtained for m-AgSAE using LS-AdSV. The developed procedures were successfully applied for TZ determination in soft drink, succade, and veterinary drug using a standard addition method. Therefore, the AgSAEs have been demonstrated to be beneficial electrochemical tools for food products’ quality and safety monitoring.