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.

[Voltammetric determination of heavy metals in meat and the internal organs of slaughter cattle]. / Die voltammetrische Bestimmung von Schwermetallen in Fleisch und inneren Organen von Schlachtrindern.

The most important uptake of heavy metal by man occurs through ingestion. Therefore heavy metal analysis of food becomes of great importance. The whole analytical procedure including sampling, transport, drying, homogenisation, digestion and measurement for the determination of Zn, Cd, Pb, Cu, Ni, and Co in meat is described with due consideration given to the requirements for trace and ultratrace analysis. The particular advantages of the voltammetric approach for heavy metal determinations in meat and meat products are generally featured by this study. A standard deviation of 3-5% RSD in the microgram/g-range and 5-10%-RSD in the ng/g-range was obtained. In order to check the accuracy of the results, mixtures of sample and standard reference material were analysed. While the Cd-content in meat is in the range of 1 ng/g (wet weight) it increases in organs, such as liver (100-500 ng/g wet weight) and kidney (600-2000 ng/g wet weight). Pb shows a similar behaviour. The levels of these elements were found to be below the maximum allowable limits set by the "Bundesgesundheitsamt", with the exception of Cd in the kidneys. There is a statistical significant correlation between the Cd and Pb contents in liver and kidney. In liver the Cu content was especially high, because there are Cu-containing enzymes in this organ. Vitamin B12 is a Co containing complex in the liver. Therefore the Co values in liver are clearly higher than those in muscle meat.