Cd is toxic to men, animals and plants. Phosphate fertilizers contain Cd in variable amounts depending on the phosphatic rock which they were obtained. Successive phosphate fertilizations can accumulate Cd in the soil, causing impacts to the environment due to its high toxicity. The purposes of this work were to quantify the Cd content in samples of 19 phosphate fertilizers used in Brazil and to compare two extraction methods: nitropercloric (HNO3-HClO4) and USEPA 3050B (HNO3-H2O2). The content of Cd in the samples were determinated by indutive spectrometric atomic emission coupled plasma (ICP-AES). Six samples presented Cd content higher than 12mg kg-1 (nitroperclóric) and one higher than 43mg kg-1. The others contained less than 3mg of Cd kg-1 fertilizer. The correlation between the Cd amounts extracted by nitropercloric and USEPA 3050B methods was significant (r = 0,985**), however, in the samples in that the content of Cd was higher than 6,0mg kg-1, the nitropercloric method extracted more Cd from the samples.
heavy metals; phosphate rock; triple superposphate
