Determination of metals in soft drinks packed in different materials by ETAAS

The present work proposes a method for the direct determination of Al, Cu, Cr, Fe and Ni in Brazilian carbonated soft drinks by electrothermal atomic absorption spectrometry (ETAAS). Samples of different flavors packed in containers made of different materials (polyterephthalate ethylene and glass bottles, and aluminum and steel cans) were analyzed. The method was optimized by building up pyrolysis and atomization curves in sample medium and by evaluating the calibration approach. Under optimized conditions, recoveries in the range of 92-104% were obtained in the evaluation of method accuracy. The limits of quantification for Al, Cu, Cr, Fe and Ni were 2.3, 0.93, 0.17, 0.90 and 1.2 μg L−1, respectively. Also, the impact of the material used in the packaging and flavor on the concentrations of each metal in the samples was evaluated. It was proved that neither flavor nor packaging material affected the concentrations of Al and Fe in the samples. On the other hand, the packaging material influenced the concentration of Cu, Cr and Ni, and only the flavor affected the concentration of Cu in the samples. These conclusions were based on the data obtained from the application of a two-way ANOVA evaluation at 95% confidence level.