[Evaluation of heavy metal contamination of potatoes from various regions of Poland].

Mercury, cadmium and lead contents were determined in 210 samples of potatoes of five cultivars, originating from four regions of Poland (Tarnobrzeg Province, Southern Region, Middle-Eastern Region, Poznań Province). Analysis was performed by the ASA method. Cadmium and lead were determined by the extraction technique, after metal complexing with APDC. Methyl isobutyl ketone was the organic phase. "Dry" mineralization of samples for cadmium and lead determinations was performed in a muffle furnace at 400 degrees C. Mercury was assayed by the cold vapour technique after "wet" mineralization with sulphuric and nitric acid in a Bethe apparatus. Mean mercury content was ca. 5.5 micrograms/kg for the samples from the uncontaminated regions; samples from the Southern Region contained on the average 12.9 micrograms/kg, i.e. twice more. Cadmium contents in potatoes from all the investigated regions were increased by an average of 0.029-0.064 mg/kg. Lead content in single samples was between 0.015-0.500 mg/kg; mean Pb contents in samples from the Southern Region, as compared with the Lublin region, were about twice higher. Hg, Cd and Pb contents were determined in the same samples of peeled potatoes and of their peels, this allowing for evaluation of the distribution of the investigated heavy metals in the tuber. It was found that lead occurs in the peels in 60-70%, and in the pulp in only 30-40%. As concerns cadmium and mercury, these metals appear in the tuber in 70-80%, and the peels in only 25-30%.