The potential of double focusing-ICP-MS for studying elemental distribution patterns in whole milk, skimmed milk and milk whey of different milks

The aim of this work was to investigate the potential of DF-ICP-MS for studying in a straightforward manner multielemental distribution patterns in human, cow and formula milks. Thus, the multielemental determination of essential and toxic elements, of primary importance, such as Na, Ca, Mg, Al, Cr, Mn, Fe, Ni, Cu, Zn, Se, Sr, Cd, Hg and Pb in whole milk, skimmed milk and milk whey by DF-ICP-MS is described. Skimmed milk and milk whey were obtained from whole milk by means of physical procedures (ultracentrifugation), without any chemical treatment. In order to destroy organic matrix, each sample was digested (before ICP-MS final analysis) by using a microwave assisted digestion method. A reference material, BCR natural skim milk powder (CRM 063) was analysed for testing the accuracy of the proposed methodology. After validation, the method has been applied to the multielemental analysis of different milk types and fractions. Results of total concentrations and distribution patterns of the above-mentioned elements in the different fractions (whole milk, skimmed milk and milk whey) of human milk, cow milk and formula milk, are presented.