[22a-C205-1~10] CS.1 Code-sharing Session of 2.3 & 7.5

[22a-C205-2] Speciation analysis of inorganic iodine isotopes in seawater

Yuanzhi Qi¹, 〇Hiroyuki Matsuzaki¹ (1.Tokyo Univ.)

Keywords:iodine-129, Inorganic iodine speciation, ocean

The global iodine cycle has a profound impact on atmospheric photochemistry, air quality, and human health. In order to delve into the iodine cycle in the ocean, the most critical iodine reservoir on earth, this study presents a comprehensive protocol for the speciation analysis of inorganic iodine isotopes (129I and 127I) in seawater. In this protocol, a coprecipitation method was improved to achieve a simple and rapid analysis of inorganic 129I in seawater. The separation efficiencies of iodide and iodate were 95% and 93%, respectively, with a cross-contamination of only 0.05%.By using this protocol, detailed distribution of iodide-129/127 and iodate-129/127 in the north Pacific ocean was obtained. This will give a novel insight to understand the global iodine geochemical cycle.