Yang Guosheng, Tazoe Hirofumi, Yamada Masatoshi
Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, China; Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing, 100049, China.
Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
Anal Chim Acta. 2018 May 30;1008:66-73. doi: 10.1016/j.aca.2017.12.049. Epub 2018 Jan 6.
To reconstruct I deposition and identify the source of radioiodine due to the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, I activity and I/I atom ratio should be obtained by preparing and analyzing large numbers of samples economically. In this study, great efforts were made to realize mild TMAH (tetramethyl ammonium hydroxide) extraction of environmental samples at 90 °C to obtain solutions suitable for the following triple-quadrupole inductively coupled plasma-mass spectrometry (ICP-QQQ) MS/MS mode analysis. After releasing iodine from organic matter in the TMAH extraction solution via KSO oxidation, organic matter was removed effectively by solvent extraction and back-extraction to avoid a serious matrix effect during ICP-QQQ analysis. At the same time, interfering elements, especially, Mo, Cd, and In were also removed effectively, to avoid their undesirable interferences during mass spectrometric analysis. In addition, 0.01% (NH)SO was selected to introduce I into ICP-QQQ to ensure there was no memory effect and a stable signal was gotten. Subsequently, ICP-QQQ MS/MS mode was applied to further eliminate polyatomic interferences (I(H and D), MoO, InO, and CdO) and isobaric interference from Xe. Finally, the developed method was successfully applied to measure I/I atom ratios ((2.61-27.0) × 10) and I activities (3.51-11.4 mBq kg) in soil samples. The developed method allows a greater number of ordinary laboratories to participate in the field of radioiodine analysis.
为了重建碘沉积并确定福岛第一核电站事故产生的放射性碘的来源，需要通过经济地制备和分析大量样品来获得碘活度和碘/碘原子比。在本研究中，我们做出了巨大努力，以实现90°C下温和的四甲基氢氧化铵（TMAH）对环境样品的萃取，从而获得适合后续三重四极杆电感耦合等离子体质谱（ICP-QQQ）MS/MS模式分析的溶液。在通过KSO氧化从TMAH萃取溶液中的有机物中释放出碘后，通过溶剂萃取和反萃取有效地去除了有机物，以避免ICP-QQQ分析过程中出现严重的基质效应。同时，干扰元素，特别是钼、镉和铟也被有效去除，以避免它们在质谱分析过程中产生不良干扰。此外，选择0.01%的（NH）SO将碘引入ICP-QQQ，以确保没有记忆效应并获得稳定的信号。随后，应用ICP-QQQ MS/MS模式进一步消除多原子干扰（I（H和D）、MoO、InO和CdO）以及来自氙的同量异位素干扰。最后，所开发的方法成功应用于测量土壤样品中的碘/碘原子比（（2.61 - 27.0）×10）和碘活度（3.51 - 11.4 mBq/kg）。所开发的方法使更多普通实验室能够参与到放射性碘分析领域。
