Uncertainty evaluation for determination of ^(14)C in urine samples by wet oxidation method  

作　　者：Linlin Yan Xiao Ge Qiang Xiong Fei Chen Jing Liang Zhen Zhang Shengyuan Yang 

机构地区：[1]School of Public Health,Hengyang Medical School,University of South China,Hengyang,Hunan 421001,China [2]National Center for Occupational Safety and Health,National Health Commission of the People's Republic of China,Beijing 102308,China

出　　处：《Radiation Medicine and Protection》2021年第4期171-175,共5页放射医学与防护（英文）

基　　金：supported by ERAN I-21-18,Key Program of Tianjin Municipal Natural Science Foundation(19JCZDJC40500);Key Program of National Center for Occupational Safety and Health(2021-ZD-06).

摘　　要：Objective:To figure out the source of uncertainty in the determination of ^(14)C activity concentration in urine samples,and to establish a complete expression of analysis results,in order to improve the accuracy of ^(14)C monitoring method.Methods:Four urine samples of normal people were collected,and wet oxidation method was used in the pretreatment of the samples,then the activity concentration of ^(14)C was determined by liquid scintillation counting(LSC).After the mathematical model was established,the uncertainty components were determined,the standard uncertainty was combined,and the extended uncertainty was calculated.Results:The relative uncertainty of 4 samples was 22.5%,17.0%,17.3%and 18.2%.The activity concentration of urine was(0.32±0.14),(0.60±0.20),(0.86±0.30)and(0.74±0.27)Bq/L,respectively.In the relative uncertainty of 22.5%,17.7%was from sample counting,13.6%from detection efficiency,2.1%from recovery rate,0.58%from sample volume,and 0.01%from sample weight.Conclusions:The main factors affecting the uncertainty include the error or deviation of sample counting,detection efficiency and recovery rate.The error of volume and weight also contributes to the measurement uncertainty.

关 键 词：^(14)C UNCERTAINTY Liquid scintillation counting URINE 

分 类 号：R81[医药卫生—放射医学]