Combined Measurement of ¹³⁴Cs, ¹³⁷Cs and ⁶⁰Co in Seawater

In the present study, the method for ¹³⁴Cs, ¹³⁷Cs and ⁶⁰Co combined measurement in seawater was set up, and the optimized experiment conditions were established. The main influence factors on ¹³⁴Cs, ¹³⁷Cs and ⁶⁰Co 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 of ¹³⁴Cs, ¹³⁷Cs and ⁶⁰Co in seawater with the optimal conditions are 87%-95%, 87%-95% and 89%-93%, respectively. The detection limits of ¹³⁴Cs, ¹³⁷Cs and ⁶⁰Co in seawater are 0.048, 0.051 and 0.046 Bq/L, respectively. In addition, the activities of ¹³⁴Cs, ¹³⁷Cs and ⁶⁰Co 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.