Neutron activation analysis of Platinum Group Elements and Gold in reference materials: A comparison between two methods

Neutron activation anaiisys methods for platinum group elements (PGEs) in geological matrices have been developed at the University of Pavia using the 250 Kw TRIGA Mark II reactor. A critical review of both instrumental and destructive methods is presented, as well as the best working conditions for irradiation, counting and radiochemical separation. Two methods have been applied to the analisis of different types of standard rocks and ores. PGEs carried out by nickel sulfide fire-assay buttons and by destructive neutron activation. Only few steps are required after irradiation, for radiochemical procedure, osmium and ruthenium separation by solvent extraction, anion exchange separation of remaining noble. Results, given as the average of five independent determinations and relative standard deviations, are presented and discussed. Precision of the methods can be deduced from the reproducibility with existing values in the literature. Sensitivity limits under the described operational conditions are also reported