Determination of Platinum‐Group Elements in Geological Samples by Isotope Dilution‐Inductively Coupled Plasma‐Mass Spectrometry Combined with Sulfide Fire Assay Preconcentration |
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| Authors: | Minghao Ren Yali Sun Christina Yan Wang Shengling Sun |
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| Institution: | 1. State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China;2. University of Chinese Academy of Sciences, Beijing, China;3. Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China;4. Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China |
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| Abstract: | A method was developed for the determination of platinum‐group elements (PGE) in geological samples by isotope dilution‐inductively coupled plasma‐mass spectrometry combined with sulfide fire assay preconcentration. Samples were fused and PGE analytes were concentrated in sulfide buttons. The buttons were dissolved using HCl leaving PGE analytes in insoluble residues, which were digested in HNO3 and simultaneously processed for the distillation of Os. The remaining solutions were further prepared for the purification of Ru, Rh, Pd, Ir and Pt using a tandem assembly of cation and Ln resin columns. The eluents were directly analysed by membrane desolvation‐ICP‐MS. Ruthenium, Pd, Os, Ir and Pt were determined by isotope dilution, whereas Rh was determined by conventional reference material calibration combined with 193Ir as the internal standard element. The method was validated using a series of PGE reference materials, and the measurement data were consistent with the recommended and the literature values. The measurement precision was better than 10% RSD. The procedural blanks were 0.121 ng for Ru, 0.204 for Rh, 0.960 ng for Pd, 0.111 ng for Os, 0.045 ng for Ir and 0.661 ng for Pt, and the limits of detection (3s) were 0.011 ng g?1 for Ru, 0.008 ng g?1 for Rh, 0.045 ng g?1 for Pd, 0.009 ng g?1 for Os, 0.006 ng g?1 for Ir and 0.016 ng g?1 for Pt when a test portion mass of 10 g was used. This indicates that the proposed method can be used for the determination of trace amounts of PGE in geological samples. |
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| Keywords: | platinum‐group elements isotope dilution sulfide fire assay geological samples é lé ments du groupe du platine dilution isotopique pyroanalyse de sulfure é chantillons gé ologiques |
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