Determination of Mineral Nutrients and Toxic Elements in Brazilian Soluble Coffee by ICP-AES

The determination of mineral nutrients and toxic elements Na, K, Mg, Al, P, S, Ca, Mn, Fe, Ni, Cu, Zn, Cd, Sb, Pb, Cr and Sn, was made in 21 samples of Brazilian soluble coffee by inductively coupled plasma atomic emission spectrometry (ICP-AES), after sample preparation in a focused microwave system with HNO3and H2O2reagents. Matrix interference was detected in the determination of Sn and the correction of the background enhancement was made by the equipment software. The results obtained for mineral nutrients and toxic elements were acceptable to human consumption at nutritional and toxic levels except for a sample with 0.52±0.02 mg/kg of Cr, a value above the specified one in the Brazilian Food Legislation. The application of the Principal Components Analysis and the Agglomerative Hierarchical Clustering on the results enabled the investigation of the variability and the classification of groups, resulting in three clusters with similarities in the mineral compositions.