Major element analysis of natural silicates by laser ablation ICP-MS

The complete chemical analysis of natural silicates has previously been accomplished only by combining laser ablation ICP-MS with electron microprobe (EMP) analysis to provide complementary information on major element constituents. Here, we present a method for laser ablation ICP-MS analysis of major elements in silicate glasses and minerals that, when applied using a 193 nm laser system coupled to an ICP-MS, provides precision and accuracy comparable to that of EMP techniques. Replicate analyses of USGS glass reference materials BCR-2G and BHVO-2G have internal precision of 1-4%, and are accurate to better than 5%. Further, the LA-ICP-MS method was applied to volume-averaged analysis of a heterogeneous silicate to yield compositions that are more precise than EMP and more accurate for minor elements, particularly MnO.