海水中^(137)Cs快速测量方法及其初步应用  

Rapid measurement method for^(137)Cs in seawater and its preliminary application

作　　者：李则书 拓飞[1] 周强[1] 杨宝路 朱卫国[1] 梁珺成[2] Li Zeshu;Tuo Fei;Zhou Qiang;Yang Baolu;Zhu Weiguo;Liang Juncheng(Key Laboratory of Radiological Protection and Nuclear Emergency,China CDC,National Institute for Radiological Protection,Chinese Center for Disease Control and Prevention,Beijing 100088,China;National Institute of Metrology,Beijing 100029,China)

机构地区：[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 [2]中国计量科学研究院,北京100029

出　　处：《中华放射医学与防护杂志》2025年第2期116-121,共6页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的建立高灵敏度的海水中^(137)Cs快速测量方法,并利用该方法开展我国沿海8个省份近岸海水中^(137)Cs测量的初步应用。方法用亚铁氰化镍钾聚丙烯腈(KNiFC-PAN)离子交换树脂材料,通过蠕动泵以60 ml/min过滤吸附海水中的^(137)Cs。采用海水中加稳定铯的方法,应用电感耦合等离子体质谱仪(ICP-MS)方法测量海水吸附前后铯离子浓度获得吸附效率。制备3个KNiFC-PAN基质成分的^(137)Cs标准样品对井型高纯锗γ谱仪进行效率刻度,获得其探测效率。以此建立海水中^(137)Cs的快速测量方法,并将该方法应用于我国沿海海水中^(137)Cs的测量。结果建立的测量方法可在6~8 h内完成20 L海水中^(137)Cs的过滤吸附,与GB/T 16145-2022标准中用磷钼酸铵-二氧化锰共沉淀方法分离海水中^(137)Cs所需时间至少要12 h相比,本研究方法在预处理海水的效率上可提升1倍,且铯回收率高达98.02%。制备的3个标准样品效率刻度值的相对标准偏差为1.30%,计算得到本方法^(137)Cs的探测下限为0.26 Bq/m^(3)。检测到我国沿海8个省份近海岸海水中^(137)Cs的活度浓度范围为0.38~1.24 Bq/m^(3)。与2019年报道我国东部海域海水中^(137)Cs活度浓度巡测结果(0.03~1.92 Bq/m^(3))和太平洋海水中^(137)Cs活度浓度(1~2 Bq/m^(3))相比,我国沿海海水中^(137)Cs处于本底水平。结论本方法具有较高的探测灵敏度,且可快速获得海水中放射性^(137)Cs的活度浓度,为我国开展海水中放射性^(137)Cs的应急监测提供了一种快速可行的方法。Objective To establish a highly-sensitive method for the rapid measurement of ^(137)Cs 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 ^(137)Cs 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 ^(137)Cs 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 ^(137)Cs 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 ^(137)Cs was 0.26 Bq/m^(3).The activity concentrations of ^(137)Cs 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 ^(137)Cs 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 ^(137)Cs in seawater,thus providing a rapid and feasible method for emergency monitoring of ^(137)Cs in China.

关 键 词：亚铁氰化镍钾聚丙烯腈 ^(137)Cs 快速测量 Γ能谱 

分 类 号：R144[医药卫生—公共卫生与预防医学]