MAJOR- AND TRACE-ELEMENT ANALYSIS OF SULFIDE ORES BY LASER-ABLATION ICP MS, SOLUTION ICP MS, AND XRF: NEW DATA ON INTERNATIONAL REFERENCE MATERIALS

Abstract

International reference materials representing a diverse suite of sulfide ores and related lithologies have been analyzed for major and trace element concentrations by XRF, solution ICP–MS, and laser-ablation ICP–MS (LA–ICP–MS) after fusion of the sample to a lithium borate glass. Reference materials analyzed for this study include a wide variety of bulk compositions, incl uding ores of Pb–Zn sulfides, Fe sulfides, Cu–Mo sulfides, and silicate matrices. Concentrations of 33 elements were determined, including lithophile and chalcophile elements of particular interest to economic geochemistry and ore deposit studies. The resu lts of LA–ICP–MS analyses were calibrated using a fused glass standard prepared specifically for the analysis of sulfides. Accuracy of the LA–ICP–MS technique is established by comparison with results obtained by the other methods for abundance variations over several orders of magnitude. Replicate analyses demonstrate a precision of 2–8% (1 RSD) for the LA–ICP–MS data at rock-equivalent concentrations >1 ppm. Matrix effects were not a significant problem at the scale of compositional variation represented by these samples, and no significant differences in the results were produced with the laser operating in either fi xedspot or line-scan mode. LA–ICP–MS analysis of fused glasses effectively overcomes problems related to insoluble phases such as cassiterite that are resistant to acid dissolution. Whole-rock analysis of sulfide ores by XRF and LA–ICP–MS provides a fast and convenient approach for determinations of major- and trace-element concentrations in a variety of ores and related material s without the need for wet-chemical dissolutions.