Nuclear and related analytical methods applied to the determination of Cr, Ni, Cu, Zn, Cd and Pb in a red ferralitic soil and Sorghum samples

Several studies on the influence of heavy metals to the growth of vegetables have been carried out in Cuba by the Ministry of Agriculture in order to evaluate the effects resulting of the continuous application of fertilizers and other materials to the soils. The analysis of metal contents in soil and vegetable samples is often troublesome due to the low concentration levels to be determined. In the the present work EDXRF, AAS and ASV methods were applied and compared for the evaluation of Cr, Ni, Cu, Zn, Cd and Pb contents in red ferralitic soil and Sorghum samples. Several certified reference materials (CRM) (inorganic and organic matrixes) were analyzed in order to evaluate the performance of the analytical procedures and the bias and precision of the results. A study was performed with growing Sorghum in several series of pots where different quantities of metals were added to the soil substrate. The observed correlation between the metal contents in soil and plants as well as the influence of different additions of each metal on the plant growth is also presented.