State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University , Beijing 100871, China.
Environ Sci Technol. 2014;48(1):534-41. doi: 10.1021/es403500e. Epub 2013 Dec 20.
An accurate and precise analytical method is highly needed for the determination of Pu isotopes in marine sediments for the long-term marine environment monitoring that is being done since the Fukushima Dai-ichi Nuclear Power Plant accident. The elimination of uranium from the sediment samples needs to be carefully checked. We established an analytical method based on anion-exchange chromatography and SF-ICP-MS in this work. A uranium decontamination factor of 2 × 10(6) was achieved, and the U concentrations in the final sample solutions were typically below 4 pg mL(-1), thus no extra correction of (238)U interferences from the Pu spectra was needed. The method was suitable for the analysis of (241)Pu in marine sediments using large sample amounts (>10 g). We validated the method by measuring marine sediment reference materials and our results agreed well with the certified and the literature values. Surface sediments and one sediment core sample collected after the nuclear accident were analyzed. The characterization of (241)Pu/(239)Pu atom ratios in the surface sediments and the vertical distribution of Pu isotopes showed that there was no detectable Pu contamination from the nuclear accident in the marine sediments collected 30 km off the plant site.
为了对福岛第一核电站事故后开展的长期海洋环境监测中的海洋沉积物中钚同位素进行测定，需要开发一种准确、精密的分析方法。需要仔细检查铀从沉积物样品中的去除情况。在这项工作中，我们建立了一种基于阴离子交换色谱和 SF-ICP-MS 的分析方法。实现了 2×10(6)的铀去污系数，最终样品溶液中的 U 浓度通常低于 4 pg mL(-1)，因此无需对 Pu 谱中的 (238)U 干扰进行额外校正。该方法适用于用大样品量 (>10 g)分析海洋沉积物中的 (241)Pu。我们通过测量海洋沉积物标准物质对方法进行了验证，结果与认证值和文献值吻合良好。对核事故后采集的表层沉积物和一个沉积物芯进行了分析。表层沉积物中 (241)Pu/(239)Pu 原子比的特征以及 Pu 同位素的垂直分布表明，在距核电站 30 公里处采集的海洋沉积物中未检测到核事故引起的 Pu 污染。
