Platinum and rhodium in a polluted environment: studying the emissions of automobile catalysts with emphasis on the application of CSV rhodium analysis

Abstract

An analytical approach is presented that utilizes CSV (cathodic stripping voltammetry) determination of Pt and Rh in polluted common grass, successfully discriminating trends in the imission situation. A sampling strategy was developed leading to clear spatial trends. It is shown that additional detection of Rh helps to confirm accuracy even of peak Pt concentrations. Applicability and reliability of CSV Rh (and Pt) detection is proven during comparative measurements in other laboratories. Independent instrumental methods (ICP-MS, docimasy) confirmed CSV results, particularly in the case of Rh. In 1997, concentrations of Pt and Rh in grass samples were found to be 2.7 times higher than in 1994, and in dust samples 3.9 times higher than in 1994, respectively. Percentage of cars equipped with catalytic converters, on the other hand, was 2.4 times higher in 1997 compared with 1994. Some of the first rhodium concentrations in environmental samples are reported.