Platinum and rhodium associated with the leaves of Nerium oleander L.; analytical method using voltammetry; assessment of air quality in the Palermo (Italy) area.

A rapid accumulation of the catalytic active noble metals in the environmental and biological matrices was observed and concern arose about potential environmental and health risks. The development of reliable analytic methods to measure very low Pt and Rh concentrations is required. The main purpose of this work was to develop a reliable method for the determination of Pt and Rh in environmental matrices because of inherent difficulties in using conventional techniques used, in particular, the ICP-OES technique. A direct determination of Pt using ICP-MS, for instance, is problematic, due to interfering signals. In this work, differential pulse voltammetry (DPV/a) and adsorptive stripping voltammetry (AdSV) were used for the determination of Pt and Rh in Nerium oleander leaves. Pt and Rh concentrations were found in the ranges 0.33-25 and 0.40-4.6 microg/kg d.w., respectively. We carried out linear regression analysis between total PAH concentrations in leaves of oleander and of Quercus ilex measured in previous researches and the data obtained in this work. The high correlation coefficients were obtained; which demonstrates that oleander leaves can be used to establish the presence and the distribution of pollutants in a chosen area.