LEAD AND CADMIUM CONTAMINATION IN DAIRY-PRODUCTS AND ITS REPERCUSSIONON TOTAL DIETARY-INTAKE

An accurate and precise method is described for the direct determinati on of lead and cadmium in dairy products, using slurried samples in co mbination with electrothermal atomic absorption spectrometry. The samp les are suspended in Triton X-100 and shaken with 10.0 g of zirconia s pheres until a slurry is formed. The slurry preparation procedure and the graphite furnace conditions were optimized for both elements. The results obtained were validated against microwave acid sample digestio n. The detection limit was 0.4 pg for Pb and 0.5 pg for Cd. The analyt ical application of this method was tested with 60 samples of 10 widel y consumed dairy products. The mean values ranged from not detectable to 0.750 mu g/g for Pb and from not detectable to 20.0 ng/g for Cd. In creased concentrations of lead and cadmium were detected in products p ackaged in glazed ceramic containers, Metal migration from the contain er was also tested. Because milk and dairy products are some of the mo st widely consumed foods in the human diet, they contribute a large fr action of the intake of trace elements. Strict control of trace elemen t levels in these foods is therefore advisable.