Instrumental neutron activation analysis (INAA) and proton induced X-ray em
ission (PIXE) analysis were used to determine the concentration of 13 eleme
nts in the breast milk collected within the first week of lactation and aft
er morning feed from 16 pre-term mothers and 20 term mothers. The results o
f the study show that pre-term milk has a significantly higher concentratio
n of Cl, Cu, Fe, K, Mg, Mn, Na and Zn while term mothers have a significant
ly higher concentration of P and Br. No significant differences were, howev
er, found in the mean concentration of Al, Ca, I and Rb. Furthermore, the m
ean concentration for most of the elements found in the breast milk fall wi
thin the range of the concentrations obtained for the commercial infant mil
k formulae.