Rapid measurement method for 137Cs in seawater and its preliminary application
10.3760/cma.j.cn112271-20240719-00268
- VernacularTitle:海水中 137Cs快速测量方法及其初步应用
- Author:
Zeshu LI
1
;
Fei TUO
;
Qiang ZHOU
;
Baolu YANG
;
Weiguo ZHU
;
Juncheng LIANG
Author Information
1. 中国疾病预防控制中心辐射防护与核安全医学所 辐射防护与核应急中国疾病预防控制中心重点实验室，北京 100088
- Publication Type:Journal Article
- Keywords:
Nickel potassium polyacrylonitrile;
137Cs;
Rapid measurement;
γ-spectrometer
- From:
Chinese Journal of Radiological Medicine and Protection
2025;45(2):116-121
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To establish a highly-sensitive method for the rapid measurement of 137Cs in seawater with an view to its preliminary application in eight coastal provinces of China. Methods:The method employed nickel potassium polyacrylonitrile (KNiFC-PAN), an organic polymer-based ion exchanged resin material, to filter and adsorb 137Cs from seawater at a rate of 60 ml/min via a peristaltic pump. The adsorption efficiency of KNiFC-PAN was determined by measuring the cesium ion concentration before and after adsorption in seawater, with the addition of stable cesium, using inductively coupled plasma mass spectrometry (ICP-MS). Three KNiFC-PAN matrix components of 137Cs standard samples were prepared for the efficiency calibration of well type high purity germanium gamma spectrometer to obtain its detection efficiency. Results:The established measuring method can complete the filtration and adsorption of 137Cs from 20 L seawater within 6-8 h, which was twice as fast as the co-precipitation method with phosphomolybdic acid-ammonium molybdate taking more than 12 h, as stipulated in the GB/T 16145-2022 standard. The cesium recovery rate was as high as 98.02%. The relative standard deviation of the efficiency calibration result for the three prepared standard samples was 1.30%, and the detection limit for 137Cs was 0.26 Bq/m 3. The activity concentrations of 137Cs in offcoast seawater in eight coastal provinces of China were detected ranging from 0.38 to 1.24 Bq/m 3. The activity concentration of 137Cs in coastal seawater of China was at the background level, while as reported in 2019 was 0.03-1.92 Bq/m 3 in the eastern Chinese seas and 1-2 Bq/m 3 in the Pacific Ocean. Conclusions:This method has high detection sensitivity and can quickly obtain the values of activity concentration of 137Cs in seawater, thus providing a rapid and feasible method for emergency monitoring of 137Cs in China.
