FOOD ANALYTICAL METHODS, cilt.8, sa.8, ss.2141-2149, 2015 (SCI-Expanded)
Separation, preconcentration, and spectrophotometric determination of tartrazine (E 102) was performed by solid-phase extraction methods with using spectrophotometry. For this purpose, Amberlite XAD-1180 and Amberlite XAD-16 resins and mini-chromatographic column were used. All absorbance measurements of the dye were determined at 427 nm. Analytical parameters including pH, sample and eluent flow rates, eluent type, ionic strength, sample volume, and adsorption isotherms were investigated and optimized. Under optimum condition interference effect of main cations, some anions and widely used dyes were examined. Detection limits of the proposed methods were determined as 5.7 and 1.2 mu g L-1 for XAD-1180 and XAD-16 resins, respectively. Linear dynamic ranges of the methods were found between 0.4-30 and 0.4-12 mu g mL(-1) of tartrazine for XAD-1180 and XAD-16 resins, respectively. The preconcentration factors were found as 60 and 80 for XAD-1180 and XAD-16 columns, respectively. Relative standard deviations were lower than 7 % throughout all experiments for two methods. Developed methods were validated and checked with determination of tartrazine levels in soft drink samples by addition of analyte. The comparisons of the methods were performed by the analysis of tartrazine contents of food samples. Tartrazine concentrations, investigated solid samples, ranged between 146 and 391 mu g/g. Tartrazine content of liquid sample was found as 7.4 and 7.3 mu g/mL for X1180 and X16 methods, respectively. The results suggest that the methods are suitable for the determination of tartrazine. Very accurate results were obtained for spiked values of the tartrazine into the food samples. In addition to accuracy, the method is simple, environmental friendly, and economical for the determination of tartrazine level in food samples. In addition of analytical parameters, adsorption and isotherm studies were performed for two kinds of Amberlite resins. It was observed that the methods fitted the linear form of Freundlich isotherm model.