Identification of chemical species of some trace and minor elements in mature breast milk

The chemical speciation of trace elements of environmental, toxicological, clinical and nutritional interest was undertaken in breast milk, with the goal of ascertaining the chemical forms of Ba, Bi, Cd, Cu, Li, Mg, Mn, Mo, Pb, Sr, Tl and Zn. At the same time, the analytical potential of size-exclusion chromatography (SEC) coupled with quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) for the purpose of chemical speciation was further explored. Breast mature milk from 30 mothers living in Turin (Italy) and its surroundings was analyzed. Total element concentrations obtained in this study were similar to those reported for human milk in other countries. As regards speciation data, these pointed to the presence in human milk of specific ligands, such as enzymes and citrates, with strong affinity for some elements, presumably increasing the bioavailability of the elements themselves. The experimental approach and the analytical method developed in this study appear adequate for the purpose and can therefore be exploited for similar investigations. (C) 2000 Elsevier Science B.V. All rights reserved.