An Analytical method of low-level radium isotopes in freshwater sample by gamma-ray spectrometry; Application of in situ pre-concentration from large volume of water sample using Powdex resin and barium sulfate coprecipitation of radium isotopes
| Autor: | Tomita, Jumpei, Abe, Takuya |
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| Jazyk: | japonština |
| Rok vydání: | 2017 |
| Zdroj: | JAEA-Research 2016-026. |
| Popis: | 本研究では、現地において大容量の淡水試料($\sim$ 170L)からRa同位体を回収する前処理法と実験室における単純な共沈法を組み合わせた$\gamma$線スペクトロメトリーによる淡水試料中の低濃度Ra同位体分析法を開発した。運搬する試料量を減容するための現地における前処理法として、Powdex樹脂によるバッチ法を検討し、Ra同位体の回収に必要な樹脂量は、水試料の電気伝導度から評価可能であることを明らかにした。また、Ra同位体を硫酸バリウム共沈法により回収することで、バックグラウンドを上昇させるKを96\%以上除去できた。既知量のRa同位体を含む電気伝導度が異なる170Lの淡水模擬試料を本手法により分析し、分析法の妥当性を確認した。この時のRaの回収率は、平均98\%、$^{226}$Ra及び$^{228}$Raの検出限界値は、それぞれ約0.3及び0.5mBq L$^{-1}$であった。 An analytical method of low-level Ra isotopes in freshwater samples with combination of {\it in situ} pre-concentration from large volume of water sample ($\sim$170 L) using Powdex resin and $\gamma$-ray spectrometry followed by simple coprecipitation of Ra was developed. {\it In situ} pre-concentration of Ra by batch method using Powder resin was examined, and it was shown that the amount of the resin required collecting Ra in the water sample could be determined by measuring the electric conductivity (EC) of water sample. It was found that coprecipitation of Ra with barium sulfate could remove more than 96\% of potassium that increases the background. The validation of this method was confirmed by the analyses of 170 L of water sample containing the known amount of Ra isotopes with different EC. Among the analyses, the recovery of Ra was 98\% in average and detection limits of $^{226}$Ra and $^{228}$Ra were achieved to be approximately 0.3 and 0.5 mBq L$^{-1}$, respectively. |
| Databáze: | OpenAIRE |
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