Platinum‐Group Elements and Gold Determination in NiS Fire Assay Buttons by UV Laser Ablation ICP‐MS

Abstract

The direct analysis of nickel sulfide fire assay buttons by UV laser ablation ICP‐MS was used to determine the platinum‐group elements and gold in the following reference materials: UMT‐1, WPR‐1, WMG‐1, GPt‐4, GPt‐6 and CHR‐Bkg. The instrument was calibrated with buttons prepared using quartz doped with the appropriate standard solutions. Analytical precision (RSD) was generally better than 10%, although occasional higher RSDs may infer local heterogeneities within nickel sulfide buttons. Good or excellent agreement was observed between analysed and reference material values except Rh in UMT‐1 and WMG‐1, which suffered an interference from copper. Detection limits calculated as 10 s quantitation limits were Au (1.7 ng g −1 ), Pd (3.3 ng g −1 ), Pt (8.3 ng g −1 ), Os (1.3 ng g −1 ), Rh (1 ng g −1 ), Ru (5 ng g −1 ) and Ir (0.7 ng g −1 ).