The following is an abstract for the selected article. A PDF download of the full text of this article is available here. Members may download full texts at no charge. Non-members may be charged a small fee for certain articles.
An Improved FeNi Sulfide Fire Assay Method for Determination of Re, Platinum Group Elements, and Os Isotopic Ratios by Inductively Coupled Plasma and Negative Thermal IonizationMass Spectrometry
Volume 63, Number 11 (Nov. 2009) Page 1232-1237
Sun, Yali; Chu, Zhuyin; Sun, Min; Xia, Xiaoping
An improved Fe-Ni sulfide fire assay method has been developed for determination of Re, the platinum group elements (PGE), and Os isotopic ratios using inductively coupled plasma-mass spectrometry (ICP-MS) and negative thermal ionization-mass spectrometry (NTI-MS). Recovery of Re using the neoclassical NiS fire assay technique is very low, but recoveries of up to 75% can be achieved by using Fe-Ni sulfide as a collector and Na2B4O7 as a flux. Using isotope dilution for determination of Re, a number of standard reference materials were analyzed for PGE and Re, and the results are consistent with their certified values. Multiple analyses of the reference standard GBW 07290 produced precisions ranging from 2.2% for Os to 5.9% for Ir. The detection limits are 2 pg g−1 for Ru, 1.5 pg g−1 for Rh, 25 pg g−1 for Pd, 23 pg g−1 for Re, 0.7 pg g−1 for Os, 1 pg g−1 for Ir, and 6 pg g−1 for Pt. The low procedural blank of Os (1.3 pg g−1) makes the Fe-Ni sulfide fire assay suitable for analysis of Os isotopic compositions. Using NTI-MS, the 187Os/188Os ratios were measured for WPR-1 and they are consistent with literature values.