Development of Microanalysis of Trace Elements in Sulfide Minerals by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry

The first-row transition metals and trace noble metals are highly enriched in sulfide minerals. Commonly, sulfides are the main ore types forming large ore deposits of industrial significance, which makes sulfide minerals of great economic value. Measurement of trace metal element abundances and spatial distributions in natural sulfide minerals are highly important in the study of ore genesis, economic geology and environment geochemistry. LA-ICP-MS is a powerful tool for microanalysis of trace elements and is suitable to directly analyze trace element abundances and spatial distributions in sulfide minerals. However, development of analysis of trace metal elements in sulfide minerals by LA-ICP-MS has been hampered by different ablation characteristics of sulfides from silicates and oxides and a serious lack of reference materials of sulfides. This paper summarizes some geological background of sulfide minerals, the analysis significance of trace metals in sulfides, the advantages and recent applications of LA-ICP-MS in quantitative analysis of major and trace elements in sulfide minerals, related argide and oxide interferences and the development of four methods of synthetic sulfide reference materials for trace elements including PGEs and Au. By comparing the four synthetic methods, it was found that the method of sintering at high temperature or high pressure is the most promising method for synthetic sulfide reference materials at present.