ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRIC DETERMINATION OF MOLYBDENUM, ALUMINUM, CHROMIUM AND MANGANESE IN MILK

Procedures for the direct determination of manganese, aluminium, chrom ium and molybdenum in cow's milk, infant formula and human milk sample s by electrothermal atomic absorption spectrometry with no sample pre- treatment are discussed. The powdered samples are suspended in a mediu m containing ethanol, nitric acid and hydrogen peroxide and directly i ntroduced into the electrothermal atomizer. In the case of molybdenum, lactalbumin is incorporated in the suspension medium. Liquid milk sam ples are diluted with the suspension medium. Calibration is carried ou t using aqueous standards. The reliability of the procedures is checke d both by comparing the results with those found after a conventional mineralization-based procedure and by analyzing certified reference ma terials. (C) 1997 Elsevier Science B.V.