title: Ultra-trace plutonium determination in small volume seawater by sector field inductively coupled plasma mass spectrometry with application to Fukushima seawater samples.
abstract: Long-term monitoring of Pu isotopes in seawater is required for assessing Pu contamination in the marine environment from the Fukushima Dai-ichi Nuclear Power Plant accident. In this study, we established an accurate and precise analytical method based on anion-exchange chromatography and SF-ICP-MS. This method was able to determine Pu isotopes in seawater samples with small volumes (20-60L). The U decontamination factor was 3×10(7)-1×10(8), which provided sufficient removal of interfering U from the seawater samples. The estimated limits of detection for (239)Pu and (240)Pu were 0.11fgmL(-1) and 0.08fgmL(-1), respectively, which corresponded to 0.01mBqm(-3) for (239)Pu and 0.03mBqm(-3) for (240)Pu when a 20L volume of seawater was measured. We achieved good precision (2.9%) and accuracy (0.8%) for measurement of the (240)Pu/(239)Pu atom ratio in the standard Pu solution with a (239)Pu concentration of 11fgmL(-1) and (240)Pu concentration of 2.7fgmL(-1). Seawater reference materials were used for the method validation and both the (239+240)Pu activities and (240)Pu/(239)Pu atom ratios agreed well with the expected values. Surface and bottom seawater samples collected off Fukushima in the western North Pacific since March 2011 were analyzed. Our results suggested that there was no significant variation of the Pu distribution in seawater in the investigated areas compared to the distribution before the accident.
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China; Research Center of Radiation Protection, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan.
authors.forename: Wenting
authors.initials: W
authors.lastname: Bu
authors.affiliation: Research Center of Radiation Protection, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan. Electronic address: jzheng@nirs.go.jp.
authors.forename: Jian
authors.initials: J
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China. Electronic address: qjguo@pku.edu.cn.
authors.forename: Qiuju
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Fukushima Project Headquarters, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Aono
authors.affiliation: Research Center of Radiation Protection, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Tagami
authors.affiliation: Research Center of Radiation Protection, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Uchida
authors.affiliation: Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tazoe
authors.affiliation: Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yamada
mesh_terms: D062406:Fukushima Nuclear Accident; D007475:Ion Exchange Resins; D007564:Japan; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000379:methods; D011005:Plutonium / Q000032:analysis*; D012623:Seawater / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D007475:Ion Exchange Resins; D011005:Plutonium
keywords: Anion-exchange chromatography; FDNPP; Plutonium; SF-ICP-MS; Seawater