Determination of platinum, palladium, rhodium and iridium in geological samples by inductively coupled plasma-mass spectrometry after the preconcentration with nickel sulphide fire assay

The preconcentration and determination of platinum, palladium, rhodium and iridium in geological samples by nickel sulphide fire assay and ICP-MS were described. The effects of various factors have been studied in detail. Alkali metals of sulfide were removed by hydrochloric acid. After filtration, the nickel sulphide button was dissolved in hydrochloric acid and peroxide, at last the four elements were determined by ICP-MS. The detection limits(ng/g) are 0.11 for Pt,0.038 for Pd,0.016 for Rh and 0.040 for Ir . The RSDs(%) are 4.09 for Pt,4.75 for Pd, 4.53 for Rh and 4.78 for Ir. The method has been applied to the determination of platinum, palladium, rhodium and iridium in geological reference materials, and the results are agreement with the certified.