Determination of metals in Brazilian soils by inductively coupled plasma mass spectrometry

The concentration of metals in Brazilian soil under no-tillage (NT) and an area under native vegetation (NV) was determined by inductively coupled plasma mass spectrometry. The applied method was based on microwave-assisted acid digestion using HNO3, HCl, H2O2, and HF. The accuracy of the method was evaluated by analyzing two certified reference materials (BCR-142 and RS-3). The relative standard deviation for all target elements was below 8% indicating an adequate precision and the limit of detection ranged from 0.03 μg g(-1) (Cd) to 24.0 μg g(-1) (Fe). The concentrations of Al, As, Ba, Cd, Cu, Fe, Mg, Mn, Ni, Pb, Sr, and Zn in the different layers (0-10, 10-20, 20-40, and 40-60 cm) were determined in two types of soils, located in Paraná State in Brazil. The soil layers analysis revealed a different behavior of metals concentrations in soil samples under NT and NV. The obtained results showed a clear impact of anthropogenic action with respect to specific metals due to many years of uncontrolled application rates of limestone and phosphate fertilizers.