Department of Nuclear Engineering and Management, The University of Tokyo, 7-3-1 Hongo, Bunkyo City, Tokyo, 113-8654, Japan.
Micro Analysis Laboratory, Tandem Accelerator, The University Museum, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
Anal Methods. 2022 Sep 29;14(37):3623-3631. doi: 10.1039/d2ay00813k.
A complete protocol is presented for the speciation analysis of I for both inorganic and organic iodine in seawater using coprecipitation and solid-phase extraction (SPE) combined with accelerator mass spectrometry (AMS). By modifying the iodide separation process and adding a crossover removal step, the improved coprecipitation method significantly reduces the cross-contamination of iodide and iodate to less than 0.05% in the speciation analysis of inorganic I, with the separation efficiencies of about 95% and 93% for iodide and iodate, respectively. The SPE-DOI method for the dissolved organic I (DOI) analysis was developed, whereby we report the first direct observation of DOI/DOI atom ratios in seawater in this paper. I species in seawater from Tokyo Bay were analysed. The I results demonstrated that our protocol for speciation analysis of I is reliable and provided new insights into understanding the iodine cycle.
本研究提出了一种完整的方案，用于使用共沉淀和固相萃取（SPE）结合加速质谱（AMS）对海水中的无机碘和有机碘进行形态分析。通过改进碘化物分离过程并添加交叉去除步骤，改进的共沉淀方法可将无机碘形态分析中碘化物和碘酸盐的交叉污染降低到 0.05%以下，碘化物和碘酸盐的分离效率分别约为 95%和 93%。本研究还开发了用于溶解有机碘（DOI）分析的 SPE-DOI 方法，首次直接观察到海水中的 DOI/DOI 原子比。对东京湾海水中的碘形态进行了分析。研究结果表明，我们的碘形态分析方案是可靠的，并为深入了解碘循环提供了新的认识。
