Novel method for low level Sr-90 activity detection in seawater by combining oxalate precipitation and chelating resin extraction

抄録

⁹⁰Sr released into seawater from nuclear bomb testing and nuclear facility accident sites requires long-term monitoring. However, measuring ⁹⁰Sr in seawater is still difficult and time-consuming. This study is aimed at improving the preconcentration method for successive purification using DGA Resin chromatography, which is applied to ⁹⁰Sr analysis in seawater. At natural pH, the oxalate coprecipitation technique effectively collected Sr (84% in Sr yield) from seawater without Mg or Na. For ⁹⁰Sr determination, ⁹⁰Y in secular equilibrium with ⁹⁰Sr was directly extracted using Fe coprecipitation and DGA Resin chromatography. The proposed method simplifies the analytical processes associated with the conventional method. Analytical results for surface seawater in the western North Pacific (0.81 ± 0.06 Bq m^–3, n = 5) were consistent with those obtained using the conventional method (0.81 ± 0.07 Bq m^–3, n = 5).