Source characterization of platinum group elements using the isotopic composition of osmium

Abstract

Environmental studies on platinum group elements (PGE) have mostly focused on platinum, palladium and rhodium owing to their use in automobile catalysts and their emission into the environment (Palacios et al., 2000). Fewer studies have dealt with the environmental relevance of the other PGE, i.e. iridium, ruthenium and osmium (Muller et al., 2000; Ely et al., 2001; Fritsche et al., 2004; Rauch et al., 2004a). Elevated Os concentrations compared with expected background have recently been reported in environmental samples and Os isotopic composition proved to be useful for source characterization (Esser et al., 1993; Ravizza et al., 1996; Williams et al., 1997; Helz et al., 2000; Rauch et al., 2004a, 2004b). Here we review the current knowledge on Os in the environment and propose an approach for PGE source characterisation using Os isotopic composition.