日本地球惑星科学連合2018年大会

講演情報

[JJ] ポスター発表

セッション記号 S (固体地球科学) » S-GC 固体地球化学

[S-GC46] 固体地球化学・惑星化学

2018年5月22日(火) 15:30 〜 17:00 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:下田 玄(産業技術総合研究所地質調査総合センター)、鈴木 勝彦(国立研究開発法人海洋研究開発機構・海底資源研究開発センター)、山下 勝行(岡山大学大学院自然科学研究科、共同)、石川 晃(東京大学大学院総合文化研究科)

[SGC46-P02] Stable iron isotope measurement with high resolution multiple collector inductively coupled plasma mass spectrometry (HR-MC-ICP-MS) at Geological Survey of Japan.

*下田 玄1後藤 孝介1野々瀬 菜穂子2申 基澈3 (1.産業技術総合研究所地質調査総合センター、2.産業技術総合研究所計量標準総合センター、3.総合地球環境学研究所)

キーワード:鉄、安定同位体、質量分析

Iron isotope ratios for standard solutions (IRMM-014 and NMIJ Fe) were measured with a Neptune Plus double-focusing ICP-MS equipped with 9 Faraday collectors (ThermoFinnigan, Bremen, Germany) at Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology. The standard solutions were introduced to the plasma ion source as dilute (2%) nitric acid solutions via an Apex Omega desolvating nebulizer system (Elemental Scientific Inc., Omaha, USA) using only argon as a sweep gas. The desolvating nebulizer system can enhance iron signal for about 20 times compared to normal spray chamber, but cannot decrease interfering signals effectively (40Ar16O > 50V). Thus, iron and interfering signals were separated by medium resolution setting of NEPTUNE Plus of which resolving power is about 4000. To reduce pulsing which may reflect droplets of solution in the desolvating chamber, uptake rate was decreased from 100-160 ul/min to 40-60 ul/min. Although this reduction reduced sensitively, a 56Fe ion signal of ca. 300 V/ppm was still routinely obtained. In this presentation, we will exhibit details of iron isotope measurement, including sample preparation, 54Fe-57Fe double spike, data reduction and mass spectrometry.