SuperLig®620用于水中90Sr含量的监测方法研究

为实现水中⁹⁰Sr的连续监测，利用SuperLig®620固相萃取颗粒从水中选择性分离和富集⁹⁰Sr，并通过塑料闪烁体测量SuperLig®620色层柱上⁹⁰Sr的含量。研究了0.2 mg/L Sr-0.01 mol/L HNO₃介质下，⁹⁰Sr在SuperLig®620色层柱上的动态平衡。结果表明，吸附平衡时⁹⁰Sr在两相间的浓度呈正比，因此通过测量柱上⁹⁰Sr的含量可得到水中⁹⁰Sr的浓度。所建立的方法对⁹⁰Sr的探测效率和最小可探测活度分别为21.3%和2.6 Bq/L，对某低放废水中⁹⁰Sr的分析误差小于20%。

Study on Monitoring of 90Sr in Aqueous Solution Using SuperLig®620

In order to achieve continuous monitoring of ⁹⁰Sr in aqueous solution, ⁹⁰Sr was firstly separated selectively and enriched by SuperLig®620 solid phase extraction beads, which was then measured in-situ using plastic scintillator. The influences of ⁹⁰Sr activity on two-phase equilibrium were studied and the results show that the concentration in aqueous solution is directly proportional to that captured on the column in 0.2 mg/L Sr-0.01 mol/L HNO₃ medium. So the concentration of ⁹⁰Sr in aqueous solution can be analyzed by detecting ⁹⁰Sr on the column. The detection efficiency and minimum detectable activity are 21.3% and 2.6 Bq/L, respectively. The concentration of ⁹⁰Sr in low level radioactive waste water was analyzed using the above method and the analytical error is lower than 20%.