Development of high-precision La isotope analysis by MC-ICP-MS

Abstract

Since ¹³⁸La is shielded from β decay paths, it can be synthesized only by supernovae. Therefore, ¹³⁸La can be used as a tracer for supernova-induced isotope anomalies in the early Solar System. Yet, the very low abundance of ¹³⁸La (0.09%) makes it difficult to conduct a precise isotope measurement. Shen and Lee (2003) found ¹³⁸La anomalies in calcium-aluminum rich inclusions by thermal ionization spectrometry, but the presence of such anomalies in bulk chondrites and achondrites remains to be tested with high-precision. To realize high-precision analysis, we have developed a La separation procedure by column chromatography and tested the precision of La isotope analysis by MC-ICP-MS.