INSTRUMENTAL NEUTRON-ACTIVATION ANALYSIS OF A NICKEL SULFIDE FIRE ASSAY BUTTON TO DETERMINE THE PLATINUM GROUP ELEMENTS AND GOLD

Platinum group elements and gold were determined in reference materials SARM 7 and MA lb using fire assay with 0.5 g of nickel prior to neutron activation analysis. The method is simple and rapid, avoiding the dissolution step where losses occur, particularly of gold. The problem of standardizing the button mass was overcome by using a spiking technique. The method is best suited to samples with little or no copper, when the detection limits can be as low as 0.002, 0.025, 0.018, 0.0002, 0.002, 0.020 and 0.2 mg kg-1 for Rh, Pd, Pt, Ir, Au, Os and Ru, respectively.