日本地球惑星科学連合2024年大会

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[J] 口頭発表

セッション記号 H (地球人間圏科学) » H-TT 計測技術・研究手法

[H-TT16] 環境トレーサビリティ手法の開発と適用

2024年5月29日(水) 10:45 〜 12:00 105 (幕張メッセ国際会議場)

コンビーナ:陀安 一郎(総合地球環境学研究所)、SHIN Ki-Cheol(総合地球環境学研究所)、谷水 雅治(関西学院大学)、座長:SHIN Ki-Cheol(総合地球環境学研究所)

11:45 〜 12:00

[HTT16-15] Sub-micro level isotope analysis of sulfur to understand its biogeochemical and ecological cycles

*小川 奈々子1吉村 寿紘1古知 武2,1黒田 潤一郎2,1高野 淑識1大河内 直彦1 (1.海洋研究開発機構、2.東京大学大気海洋研究所)

キーワード:超高感度 EA/IRMS、硫黄同位体比分析、硫酸、陰イオンクロマトグラフィー、硫酸バリウム

The use of isotopic abundance ratios to trace and interpret the movement of materials has been widely recognized in various fields. In many cases, the breakthroughs in these studies have been accompanied by advances in analytical techniques, demonstrating the close interrelationship between the development of analytical methods and the progress of scientific research. This includes not only analytical instruments for isotope detection but also pre-processing techniques for preparing the target substances for isotope analysis. In the case of the biological element (CNSHO) isotope studies, the development of various on-line or off-line pretreatment techniques, from cryogenic isolation under vacuum conditions in the early days to carbonate devices, elemental analyzers, capillary gas chromatography, liquid chromatography, etc., has supported the progress of the research. The true potential of high-precision detection devices, such as isotope ratio mass spectrometers, is enhanced when coupled with excellent pre-processing methods, and these often serve as important catalysts for advancing science.
From this perspective, our research group has been developing ultra-sensitive isotope analysis techniques based on meticulous pre-processing methods. In this presentation, we will introduce the newly developed δ34S analysis for trace amounts of sulfate and discuss its potential applications through some examples of environmental sample data. The anion chromatographic fraction collection method (ICFC method) detects and separates a few tens nmol of sulfate, and the micro-barite formation technique (μ-Barite method), which converts collected sulfate into barite crystals introduces 5-50 nmol of sulfur into an isotope analyzer without loss. Together with the already established nano EA/IRMS system, these techniques will broaden the scope of studies using δ34S.
Although sulfur is present in the atmosphere and ocean in various forms and plays an important role in maintaining life, there remain many unexplored links between its isotopic characteristics and biogeochemical cycles. This presentation aims to discuss the technical details of our new method, its potential advantages, practical applications, and challenges to be overcome.