NAA and UV laser ablation ICP-MS for platinum group elements and gold determination in NiS fire assay buttons: A comparison between two methods

NAA and UV laser ablation ICP-MS were used to determine platinum group elem ents (PGEs) and gold in the geological reference materials UMT-1, WPR-1, WM G-1, GPT-4 and GPt-6, after NiS fire assay. Both methods presented results were good agreement with the recommended values. NAA gave more accurate val ues for Ir (relative errors between 0 to 9%) and UV-LA-ICP-MS presented bet ter results for Pt (relative errors less than 12%, except for WPR-1). UV-LA -ICP-MS showed better sensitivity than NAA for Pd and Os. On the other hand , NAA showed lower detection limits for Ir and Au. Advantages and disadvant ages of each method are discussed.