Concentrations of trace elements in extensively hydrolysed infant formulae and their estimated daily intakes

The 18 trace elements Ba, Be, Bi, Cd, Co, Cs, Cu, La, Li, Mn, Mo, Pb, Rb, Sb, Sn, Sr, Tl, and Zn were determined in three extensively hydrolysed formulae by inductively coupled plasma mass spectrometry. Two formulae were whey hydrolysates, whereas one was based on soy-bovine collagen hydrolysate. Two skim milk powder reference materials, analyzed to ensure the analytical precision and accuracy of the applied procedure, showed good agreement with the certified values. Most of the elemental concentrations in this three formulae were comparable to each other. However, concentrations of Cs in one formula were approximately 20 times higher than in the other two formulae. Another formulae had much higher concentrations of La and Mn compared to the other two formulae. As regards Rb, all three formulae had distinctly lower concentrations than the four pre- and nine follow-up formulae investigated in a previous study. For the essential trace element Sn, much higher concentrations were found in the three extensively hydrolysed formulae ( approximately 8 microg/kg) when compared to pre- and follow-up formulae (most of them <0.44 microg/kg). The concentrations of the toxic trace elements Cd, Pb, Sb, and Tl in extensively hydrolysed formulae did not exceed the concentrations in cow-milk-based formulae. Daily intakes provided by the investigated formulae differ by a factor of 1.6 for Co, of 3.2 for Cu, of 8.7 for Mn, of 4.8 for Mo, and of 1.5 for Zn. Adequate daily intakes for Cu, Mo, and Zn are guaranteed by the use of most formulae, whereas only one hydrolysed formula fulfilled these requirements for manganese. Two hydrolysed formulae provide only approximately 50% of the recommended intakes for Mo.