Determination of ruthenium,rhodium,palladium,osmium,iridium and platinum in anode copper by inductively coupled plasma mass spectrometry with nickel sulfide fire assaying

Besides being rich in major elements like copper, anode copper also contains relatively high levels of platinum group metals. Accurate determination of their content is crucial for optimizing smelting processes, assessing metal recovery rates, and controlling production workflows. In this study, a method based on nickel sulfide fire assay was established for the separation, enrichment, and determination of the six platinum group elements (PGEs: ruthenium, rhodium, palladium, osmium, iridium, and platinum) in anode copper samples. This method achieves efficient capture of PGEs through nickel sulfide fire assay and effectively eliminates matrix interference by combining the pulverization and dissolution characteristics of the nickel sulfide button with detection by inductively coupled plasma mass spectrometry (ICP-MS), thereby avoiding interference from matrix elements such as copper and nickel during ICP-MS determination. The results showed that under the optimal conditions (2 g sublimed sulfur, 15 g silicon dioxide, 5 g sodium nitrate, 10 g calcium fluoride, a covering agent of light magnesium oxide mixed with silicon carbide at a 3∶1 mass ratio, 1 050 ℃, and 20 min holding time), the nickel sulfide button exhibited a uniform texture and could be completely separated from the slag, significantly improving the enrichment efficiency of PGEs. When applied to the determination of the six PGEs in anode copper samples, this method yielded relative standard deviations (RSD, n=7) of 0.64% to 2.1%. The relative errors for the six PGEs in simulated samples ranged from -1.12% to 2.13%.