CHEMOMETRIC STUDIES ON MINOR AND TRACE-ELEMENTS IN COWS MILK

In raw milk nine minor and trace elements (Cr, Mn, Fe, Ni, Cu, Zn, Mo, Cd and Pb) were determined in the dissolved ash by means of atomic absorption spectrometry and electrothermal atomization in a graphite furnace. The application of linear principal component analysis to the data matrix has permitted the reduction of the number of variables to four principal components accounting for 74% of the total variability. The two-dimensional plot of the scores (the milk samples) for the first principal components has pointed out a differentiation according to the two kinds of cow's feeding. Successively, the technique of linear discriminant analysis has fully confirmed the separation between the two types of milk.