Platinum‐Group Element and Rhenium Concentrations in Low Abundance Reference Materials

Abstract

One or two gram aliquots of twelve reference materials with low platinum‐group element (PGE) abundances (Ir concentrations ranging from 30 to 510 pg g ‐1 ) were analysed by isotope dilution ICP‐MS using an on‐line chromatographic matrix separation after acid digestion in a high pressure asher (HPA‐S) to determine the concentrations of Ru, Pd, Re, Ir and Pt. Osmium concentrations were determined via ID‐ICP‐MS but as volatile OsO 4 , whereas Rh concentrations were calculated by comparing the peak areas of the chromatographic peak with that of a standard solution. Validation of the method was performed and the concepts of traceability and measurement uncertainty were applied to assure comparability. The reference materials BCR‐2, BHVO‐1, BHVO‐2, BIR‐1, DNC‐1, EN026 10D‐3, MAG‐1, RGM‐1, SCo‐1, SDO‐1, TDB‐1 and W‐2 were investigated to test for their usefulness for certification. The use of TDB‐1 is highly recommended because it is homogeneous at the two gram level and many values based on several different analytical procedures have been published. It is recommended that our efforts should focus on the certification of this reference material to reduce the uncertainties of its currently certified values (Pd and Pt only) and to assign certified values to the other PGE and Re. It is necessary to have at least one well‐characterised RM for validation of methods applied to the analysis of PGE and Re in low abundance samples, although the matrix of TDB‐1 might not completely match those of many samples.