日本質量分析学会 第68回質量分析総合討論会会

演題概要

ポスター発表

第3日 5月13日(水)  P会場(1008/09)

高時間分解能・多重検出器型ICP質量分析法を用いた隕石中のナノ粒子の白金同位体比分析法の開発

(東大院理)
o沼倫加中里雅樹山下修司平田岳史

Both the origin and transport mechanism of heavy elements (Fe–U) are important to decode the chemical evolution of the Galaxy. Isotopic signatures of the nano-sized grains preserved in meteorites can provide key information concerning the nucleosynthetic processes of the heavy elements. In this study, we have developed a new mass spectrometric technique using multiple collector-ICP-mass spectrometer equipped with high time-resolution data acquisition system (HTR-MC-ICP-MS) to obtain isotopic ratio data from individual nanoparticles (NPs) in meteorites. To evaluate the accuracy of data obtained by this method, isotopic ratios of 195Pt/194Pt for commercially available Pt NPs were measured. The 195Pt/194Pt ratio data obtained in this study revealed that the resulting precisions in the isotopic ratio measurements were mainly controlled by the Poisson counting statistics. The analytical technique developed here was applied to measure 195Pt/194Pt and 196Pt/194Pt ratios for NPs which were extracted from Allende meteorite through the laser ablation in liquid (LAL) technique. Among these samples, 80 nano-sized grains in total with Pt were detected and measured for their isotopic signatures. We will present the variation of the measured Pt isotopic ratios for meteoritic NPs to discuss the possible nucleosynthetic process of Pt isotopes.