- 著者
- Kanoko Kurihara Norika Numa Sota Niki Mai Akamune Masaki Nakazato Shuji Yamashita Shoichi Itoh Takafumi Hirata
- 出版者
- GEOCHEMICAL SOCIETY OF JAPAN
- 雑誌
- GEOCHEMICAL JOURNAL (ISSN:00167002)
- 巻号頁・発行日
- vol.57, no.5, pp.e9-e16, 2023 (Released:2023-10-24)
- 参考文献数
- 35
Elemental and isotopic analyses of individual submicron-sized particles in chondrite matrix were made by an inductively coupled plasma time-of-flight mass spectrometer (ICP-TOF-MS) and a multiple collector ICP-MS equipped with high-time-resolution ion counters (HTR-MC-ICP-MS). The particles were collected from Allende CV3 chondrite through a laser ablation-in-liquid (LAL) technique. Firstly, the abundances for four major elements (Si, Al, Mg, and Fe) were determined on total 6086 particles, indicating that the Allende matrix is a mixture of submicron-sized particles made mainly of olivine, pyroxene, spinel, Fe–Ni sulfide, and Fe–Ni metal, consistent with the predicted major constituent minerals by a nebular condensation model. The major elemental compositions revealed that Fe–Ni particles are minor components (about 0.3% in number fraction) in the Allende matrix. Then, to estimate the origin of these metallic particles, abundances for Ni and two minor elements (Os and Pt) were measured. Total 10417 particles of Ni–Os–Pt bearing particles were also found in the chondrite matrix. Majority of the particles were enriched in Ni. Os and Pt were present as separated particles, and no particles with presence of both the Os and Pt were found. Finally, with the HTR-MC-ICP-MS technique, 195Pt/194Pt value was measured on total 1545 particles. The resulting 195Pt/194Pt values agree with the solar composition within analytical uncertainties. This lack in isotopic anomalies of the 195Pt/194Pt can be explained either by majority of the Pt nuggets being produced from uniform reservoir in the solar system or by Pt being isotopically homogenized prior to the formation of the solar nebula.
- 著者
- Takafumi Hirata Shuji Yamashita Mirai Ishida Toshihiro Suzuki
- 出版者
- The Mass Spectrometry Society of Japan
- 雑誌
- Mass Spectrometry (ISSN:2187137X)
- 巻号頁・発行日
- vol.9, no.1, pp.A0085, 2020-06-10 (Released:2020-06-12)
- 参考文献数
- 45
- 被引用文献数
- 12
We measured the Re/Os (185Re/188Os) and 187Os/188Os ratios from nanoparticles (NPs) using a multiple collector-inductively coupled plasma-mass spectrometer equipped with high-time resolution ion counters (HTR-MC-ICP-MS). Using the HTR-MC-ICP-MS system developed in this study, the simultaneous data acquisition of four isotopes was possible with a time resolution of up to 10 μs. This permits the quantitative analysis of four isotopes to be carried out from transient signals (e.g., <0.6 ms) emanating from the NPs. Iridium–Osmium NPs were produced from a naturally occurring Ir–Os alloy (ruthenosmiridium from Hokkaido, Japan; osmiridium from British Columbia, Canada; iridosmine from the Urals region of Russia) through a laser ablation technique, and the resulting nanoparticles were collected by bubbling water through a suspension. The 187Os/188Os ratios for individual NPs varied significantly, mainly due to the counting statistics of the 187Os and 188Os signals. Despite the large variation in the measured ratios, the resulting 187Os/188Os ratios for three Ir–Os bearing minerals, were 0.121±0.013 for Hokkaido, 0.110±0.012 for British Columbia, and 0.122±0.020 for the Urals, and these values were in agreement with the ratios obtained by the conventional laser ablation-MC-ICP-MS technique. The data obtained here provides a clear demonstration that the HTR-MC-ICP-MS technique can become a powerful tool for monitoring elemental and isotope ratios from NPs of multiple components.