土壤样品中~(137)Cs和~(210)Pb活度分析比对研究

本文介绍了国际原子能机构(IAEA)组织的5个土壤样品中137Cs和210Pb活度分析的国际比对结果。本实验室比对用HPGe低本底γ谱仪对土壤样品进行测量,用LabSOCS(Laboratory Sourceless Calibration Software)进行系统无源效率刻度。通过IAEA的评价指标对结果进行评价表明,所测定的5个土壤样品中137Cs和210Pb活度结果都满足达标的要求,成功通过了IAEA的比对。IAEA公布的所有参加的18个实验室的比对结果显示,137Cs活度测定结果有82%的实验室属可接受,而210Pb活度测定结果只有33%的实验室属可接受。对这次国际比对总结分析经验和不足:137Cs与210Pb相比,其分析不确定性相对小,分析误差容易控制;210Pb是土壤中本身存在的放射性核素,其穿透能力较低,受土壤母质和本底的影响,其分析误差不容易控制。

ASSESSMENT OF THE PROFICIENCY TEST ON THE DETERMINATION OF ~(137)Cs AND ~(210)Pb IN SPIKED SOIL

This article summarized the results on the IAEA-CU-2006-02 proficiency test on the determination of 137Cs and 210Pb in spiked soil.LabSOCS(Laboratory Sourceless Calibration Software)was used to perform mathematical efficiency calibration of HPGe low-background gamma-spectrometry.The analytical data evaluation of this proficiency test according to the performance criteria of IAEA indicated that 100% of the laboratory of the Institute of Agricultural Environment and Sustainable Development reported "acceptable" results for the 137Cs and 210Pb.And the analytical data evaluation of this proficiency test in IAEA's report indicated that 82% of the eighteen laboratories reported "acceptable" results for 137Cs and 33 % for 210Pb.Through this proficiency test,we could know the successful experiences and existed shortcomings.The uncertainty of 137Cs measurement was lower than 210Pb,the analytical error was easy to control.210Pb was the inherent radionuclides existed in the soil,the penetrating power was low,influenced by the soil parent material and the background,the analytical error was difficult to control.