A New Spectrophotometric Method for Determination of Tartrazine in Saffron Samples Based on Modified Magnetic Graphene Oxide Nanocomposite

Quality control in agricultural products has always been noticed. In the present study, a new pre-concentration technique for the determination of Tartrazine (TZ) in saffron samples by employing Fe3O4/Graphene oxide-COOH as an adsorbent is presented. Fe3O4/Graphene oxide-COOH was prepared and characterized by scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FT-IR). After extraction, the TZ concentration was measured by the UV-Vis spectrophotometer. The important factors for pre-concentration such as sample pH, amount of adsorbent, contact time and eluent volume were examined and optimum conditions were obtained. The new proposed spectrophotometric method shows good dynamic range of 0.02 to 10 mg/L (R2>0.996) for TZ with a limit of detection (LOD) of 0.01 mg/L after pre-concentration. This method was applied to the analysis of TZ in saffron samples and recovery values and enrichment factor were found as 94% and 5, respectively. Finally, 5 saffron samples were spiked with TZ and analyzed with new spectrophotometric methods, and results compared by HPLC as a standard method. The results of the t-test showed that there is no significant difference between the two methods.