Simultaneous determination of sunset yellow and tartrazine in soft drinks samples using nanocrystallites of spinel ferrite- modified electrode

The ZnCrFeO4 nanoparticles were synthesized as antiferromagnetic material using sol-gel method. The X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) certified that ZnCrFeO4 nanoparticles have single-phase cubic structure with a range of 50–100 nm in size. A facile and sensitive analytical method was developed for simultaneous determination of sunset yellow and tartrazine based on ZnCrFeO4 modified paste electrode.  The oxidation responses of sunset yellow and tartrazine are improved extremely at the modified carbon paste electrode (ZnCrFeO4/CPE), exhibiting two well-defined anodic peaks at + 0.70V and +0.99 V vs Ag/AgCl, respectively.  The oxidation reactions were controlled by diffusion step for tartrazine and adsorption step for sunset yellow. Simultaneous determination of these dyes indicated wide linear ranges from 0.07 to 47.5, and 0.05 to 19.0 μmol L−1 with detection limits of 2.0 and  10.0 nmol L−1  for sunset yellow and tartrazine, respectively. The results of real samples analyses  affirmed that ZnCrFeO4/CPE possess remarkable potential to determine simultaneously sunset yellow and tartrazine in soft drinks samples.