Determination of rare earth element in carbonate using laser-ablation inductively-coupled plasma mass spectrometry: An examination of the influence of the matrix on laser-ablation inductively-coupled plasma mass spectrometry analysis

In this study, we examined the influence of the matrix on rare earth element (REE) analyses of carbonate with laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) using carbonate and NIST glass standards. A UV 213 nm Nd:YAG laser system was coupled to an ICP-MS. Laser-ablation was carried out in both He and Ar atmospheres to investigate the influence of ablation gas on the analytical results. A small amount of N2 gas was added to the carrier gas to enhance the signal intensities. Synthetic CaCO3 standards, doped with REEs, as well as NIST glasses (NIST SRM 610 and 612) were used as calibration standards. Carbonatite, which is composed of pure calcite, was analyzed as carbonate samples. The degree of the influence of the matrix on the results was evaluated by comparing the results, which were calibrated by the synthetic CaCO3 and NIST glass standards. With laser-ablation in a He atmosphere, the differences between the results calibrated by the synthetic CaCO3 and NIST glass standards were less than 10% across the REE series, except for those of La which were 25%. In contrast, for the measurements made in an Ar atmosphere, the results calibrated by the synthetic CaCO3 and NIST glass standards differed by 25–40%. It was demonstrated that the LA-ICP-MS system can provide quantitative analysis of REE concentrations in carbonate samples using non matrix-matched standards of NIST glasses.