Microwave Preparation of Geological Samples in UltraWAVE System for the Determination of Platinum Group Elements and Rhenium by Mass-Spectrometric Isotope Dilution

—We report the first results of the application of UltraWAVE reactor-type microwave system for geological sample preparation ( T = 250°C and P up to 80 bar) with a mixture of concentrated nitric and hydrochloric acids (3 : 1). Determination of the platinum group elements – Ru, Pd, Ir, Pt (PGE) and Re after acid digestion was carried out by isotope dilution using the high-resolution mass-spectrometer ELEMENT after chromatographic separation of analytes on an AG50Wx8 cation exchange resin. The monoisotopic rhodium was determined with 195 Pt as an internal standard. The achieved detection limits were from 0.003 ng/g (Ir) to 0.09 ng/g (Pt). The correctness of the new procedure was confirmed by the analysis of geological reference samples—GP-13, UB-N, BHVO-2. The proposed procedure significantly accelerates and simplifies the preparation of geological samples for PGE and Re determination compared to the Carius tube technique.