海水中134Cs、137Cs和60Co的联合分析

建立了小体积海水中¹³⁴Cs、¹³⁷Cs和⁶⁰Co的联合分析方法，确定了最佳实验条件。采用磷钼酸铵富集法对海水中放射性铯进行浓集后，其上清液利用氢氧化钴沉淀载带海水中的⁶⁰Co，用γ能谱仪进行测量。结果表明：该法对海水中放射性¹³⁴Cs、¹³⁷Cs和⁶⁰Co的回收率分别为87%~95%、87%~95%和89%~93%，检测限分别为0.048、0.051、0.046 Bq/L。另外，对2017年IAEA国际比对（IAEA-RML-2017-01）海水样品中的¹³⁴Cs、¹³⁷Cs和⁶⁰Co进行分析测量，核素分析结果的最终评价均为“通过”，验证了本实验室采用的¹³⁴Cs、¹³⁷Cs和⁶⁰Co联合分析方法的可行性和可靠性，为今后该方法在常规海洋环境放射性监测中的应用推广奠定了基础。

Combined Measurement of134Cs, 137Cs and60Co in Seawater

In the present study, the method for¹³⁴Cs,¹³⁷Cs and ⁶⁰Co combined measurement in seawater was set up, and the optimized experiment conditions were established. The main influence factors on¹³⁴Cs,¹³⁷Cs and⁶⁰Co determination in seawater, such as AMP addition, pH values, Cs carrier addition, Co carrier addition were studied. The experimental results show that the recovery rate of¹³⁴Cs,¹³⁷Cs and⁶⁰Co in seawater with the optimal conditions are 87%-95%, 87%-95% and 89%-93%, respectively. The detection limits of¹³⁴Cs,¹³⁷Cs and⁶⁰Co in seawater are 0.048, 0.051 and 0.046 Bq/L, respectively. In addition, the activities of¹³⁴Cs,¹³⁷Cs and⁶⁰Co in spiked seawater provided by IAEA in 2017 (IAEA-RML-2017-01) were determined. Our results pass all criteria for the accuracy, precision and trueness which are assigned “Accepted” statuses. The established method can be applicable for routine monitoring of radiocesium and radiocobalt in seawater.