Comparison of two methods for determination of low level 137Cs activity concentration in food sample
10.3760/cma.j.cn112271-20240301-00081
- VernacularTitle:食品样品中低水平 137Cs活度浓度测量的两种方法比较
- Author:
Qishan ZHENG
1
;
Lihua HUANG
;
Yanqin JI
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
- Keywords:
Food;
137Cs;
Uncertainty;
Detection limit
- From:
Chinese Journal of Radiological Medicine and Protection
2024;44(5):393-398
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To study the applicability of conventional detection method, gamma spectrometry and radiochemical analysis, for the determination of 137Cs activity concentratons in food samples and to compare the difference of such two methods for this purpose. Methods:By using both γ spectrometry and radiochemical analysis, the activity concentrations of 137Cs in different types of food were determined, to compare the required sample amounts, the sample pretreatment and preparation processes and the lower detection limits.With meat samples as a case study, the two method were compared for assessing the activity concentrations of 137Cs in meat samples and evaluating the uncertainties. Results:The deviation of measurement result obtained in meat by using gamma spectrometry and ammonium phosphomolybdate-β counting method is consistent, with relative extended uncertainties of 18.0% and 8.0%, respectively. The pretreatment process for γ spectrometry is characterized by its simplicity, but large sample amount required and time-comsuming process, while the ammonium phosphomolybdate method requires a small amount of sample but in need of separation and purification process.The detection limits of the two methods are 10.6 mBq/kg (sample mass 11.7 kg) and 5.1 mBq/kg (sample sample 2.1 kg ), respectively.Conclusions:The results of two methods for determinationf of the low activity concentrations of 137Cs in food samples are consistent. Therefore, when monitoring low activity concentrations of 137Cs in food samples, the appropriate detection method can be selected based on the specific objective and requirements of the monitoring study.
