Biospheric Assessment for Waste Disposal Team, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 491 Anagawa, Inage, Chiba, 263-8555, Japan.
Laboratory of Marine Isotopic Technology and Environmental Risk Assessment, Third Institute of Oceanography, State Oceanic Administration, Xiamen, 361005, China.
Sci Rep. 2018 Jan 30;8(1):1892. doi: 10.1038/s41598-018-20151-4.
In order to assess the impact of the Fukushima derived Pu isotopes on seawater, a new analytical method to rapidly determine Pu isotopes in seawater by SF-ICP-MS including Fe(OH) primary co-precipitation, CaF/LaF secondary co-precipitation and TEVA+UTEVA+DGA extraction chromatographic separation was established. High concentration efficiency (100%) and high U decontamination factor (10) were achieved. The plutonium chemical recoveries were 74-88% with the mean of 83 ± 5%. The precisions for both Pu/Pu atom ratios and Pu activity concentrations were less than 5% when 15 L of seawater samples with the typical Pu activity of the Northwest Pacific were measured. It just needs 12 hours to determine plutonium using this new method. The limit of detection (LOD) for Pu and Pu were both 0.08 fg/mL, corresponding to 0.01 mBq/m for Pu and 0.05 mBq/m for Pu when a 15 L volume of seawater was measured. This method was applied to determine the seawater samples collected 446-1316 km off the FDNPP accident site in the Northwest Pacific in July of 2013. The obtained Pu activity concentrations of 1.21-2.19 mBq/m and the Pu/Pu atom ratios of 0.198-0.322 suggested that there was no significant Pu contamination from the accident to the Northwest Pacific.
为了评估福岛衍生的 Pu 同位素对海水的影响，建立了一种新的分析方法，通过 SF-ICP-MS 快速测定海水中的 Pu 同位素，包括 Fe(OH)3 一次共沉淀、CaF/LaF2 二次共沉淀和 TEVA+UTEVA+DGA 萃取色层分离。实现了高浓度效率（100%）和高 U 去污因子（10）。当测定西北太平洋典型 Pu 活度的 15 L 海水样品时，Pu 的化学回收率为 74-88%，平均值为 83±5%。当测定西北太平洋 15 L 海水样品时，Pu/Pu 原子比和 Pu 活度浓度的精密度均小于 5%。使用这种新方法仅需 12 小时即可测定 Pu。Pu 和 Pu 的检出限（LOD）均为 0.08 fg/mL，相当于测定 15 L 海水时 Pu 的检出限为 0.01 mBq/m，Pu 的检出限为 0.05 mBq/m。该方法应用于 2013 年 7 月在西北太平洋距离 FDNPP 事故现场 446-1316 km 处采集的海水样品。获得的 Pu 活度浓度为 1.21-2.19 mBq/m，Pu/Pu 原子比为 0.198-0.322，表明事故对西北太平洋没有造成明显的 Pu 污染。
