固相萃取片法分析土壤样品中的^(239)Pu

Solid Phase Extraction Disk Procedure to Determine ^(239)Pu in Soils

为了对核设施及周边环境的放射性污染水平进行有效监测,需要对土壤样品中的^(239)Pu进行分析。本研究考察了静态吸附中介质酸度、接触时间以及温度对^(239)Pu在固相萃取片上的吸附影响,确定最佳吸附条件;采用柱实验进行验证,以固相萃取片法为分离纯化手段,采用高酸上柱,低酸条件下还原解吸,以低本底液闪谱仪为放射性测量手段,建立快速分析土壤中^(239)Pu的方法。该方法可测土壤样品量为10g,使用8mol/L HNO_3浸取灰化后的模拟污染土壤样品,模拟土壤样品中^(239)Pu的化学回收率为78.9%,比活度探测下限为3.7 Bq/kg,全流程分析时间小于3h,对核素^(137)Cs、^(90)Sr-^(90)Y、天然铀、^(241)Am、^(99)Tc去污效果良好,该方法可广泛应用于环境土壤样品的^(239)Pu分析。

^ 239 Pu in many soil samples should be analyzed to survey radioactive pollution level in nuclear facilities and its affinity environment efficiently. In order to input the opt conditions for column experiment, the experiments of the static adsorption coeffi-cient of 239 Pu to solid phase extraction disk with different contact time, concentration of HNO3 and different temperature were carried out. The chemical procedure for the rapid separation and determination of 239 Pu in soils had been formulated, which using solid phase extraction disk （Empore Anion Exchange-SR） as extraction material and liquid scintillation spectrometry counting as measurement. In the procedure, soil sample usage was 10 g, and were leached by 8 mol/L HNO3 , the chemical recovery of the procedure was about 78. 9%, and the minimum detectable concentration was 3. 7 Bq/kg. It took less than 3 hours once and the presence of ^137 Cs, ^90 Sr- ^90 Y and natural uranium, ^241 Am, ^99Tc did not interfere with the procedure, owning high DF of them. The procedure can be used extensively in determination of 239 Pu in soils.