Determination of the platinum group elements in geological samples by ICP-MS after NiS fire assay and Te coprecipitation: ultrasound-assisted extraction of PGEs from Te precipitate

Abstract

A method for the determination of the platinum group elements in geological samples by ICP-MS after NiS fire assay and Te coprecipitation has been developed. With the aim of controlling the volatility of OsO₄ and reducing the number of procedural blanks of platinum-group elements (PGEs) as a whole, an ultrasound-assisted extraction technique was attempted for the dissolution of the Te precipitate at low temperature, which prevented the loss of Os. Total blanks were less than 0.12 ng g⁻¹ and method detection limits (3σ, n = 11) were within 0.006–0.039 ng g⁻¹ for all elements. The proposed method was successfully applied to the simultaneous determination of all PGEs in the geological certified reference materials; the results were found to be in reasonable agreement with the certified values. The precisions that were evaluated with the seven replicate results of GBW 07290 and SARM-7 were within the range from 1.1%–7.7% RSD.