High precision uranium isotope ratio measurement using a novel MC-ICP-MS

Abstract

The use of MC-ICP-MS for the measurement of uranium isotope ratios is now commonplace in both geochemical (e.g. geochronology) and nuclear science (e.g. non-proliferation) applications. It is typically faster and less demanding of sample preparation time than comparable techniques such as Thermal Ionization MS (TIMS).However, the ultimate performance in terms of precision and accuracy still cannot match TIMS, mostly due to the inherent instabilities in the ionization technique. The performance of the current generation of instruments is also constrained by detector limitations, including the regular requirement to cross-calibrate between different detector technologies.We show uranium isotope ratio data taken with a totally new MC-ICP-MS platform. This prototype instrument exhibits excellent mass bias stability and abundance sensitivity. It also uses the unique ATONA technology from Isotopx, a system known for extremely low Faraday detector noise couple to very high dynamic range. These factors combine to produce precise, reproducible uranium isotope ratios for a range of sample sizes, potentially improving the future analytical capabilities of MC-ICP-MS for the analysis of uranium and other actinides.