Metal analysis in difficult materials with platform furnace Zeeman-atomic absorption spectroscopy. 2. Direct determination of cadmium and lead in milk.

A procedure is described for the direct determination of cadmium and lead in whole milk, skim milk, condensed milk, and human milk. Using a Perkin-Elmer 5000 Z instrument with HGA 500 and L'vov platform and by application of oxygen ashing at approx. 600 degrees C, determination limits of approx. 0.02 microgram/l and 0.7 microgram/l for cadmium and lead, respectively, are attainable. Day-to-day precision is 10% for 0.1 microgram/l of cadmium and 2 micrograms/l of lead. Accuracy control at least at higher levels was possible with DPASV after wet digestion. The contents found with this procedure in cows milk are at the lowest limit of very recent literature data, i.e. on average at 0.05 microgram/l for cadmium and 2 microgram/l for lead for samples from nonpolluted regions. The results indicate that milk does not contribute significantly to heavy metal exposure of man.