ABSTRACT

All platinum group element (PGE) abundances of a standard rock JP-1 are determined by isotope dilution method (for Ru, Pd, Os, Ir and Pt) and external calibration method (only for Rh) using ICP-MS combined with a fire assay preconcentration technique. The errors range 13–25% (2σ; n = 5), which are comparable with those by the similar methods combined with chemical separation of PGE (Pearson and Woodland, 2000; Meisel et al., 2001). Large deviations between our data and preferable values proposed by the Geological Survey of Japan (GSJ) are observed for Os and Ir. The scattered Os data might be indicative of heterogeneity of Os in JP-1. From various viewpoints, it seems likely that our Ir data are much more reliable than the preferable values proposed by GSJ.