从^(237)Np中分离高纯度^(233)Pa的硅胶树脂法研究

Separation of Highly-purified ^(233)Pa from ^(237)Np with Silica Gel Column

采用硅胶树脂法从237Np中分离得到高纯度的233Pa.研究发现,当7mol/L HNO3237Np-233Pa平衡溶液通过硅胶树脂时,237Np会随着流洗液流出,在无F-存在的条件下,233Pa会吸附在硅胶树脂上,在F-存在的条件下,可以将233Pa从硅胶树脂上洗脱下来.不同HF浓度(7mol/L HNO3+HF混合溶液)的实验结果显示,7mol/L HNO3+0.15mol/L HF溶液能够有效地将大部分233Pa从硅胶树脂上洗脱下来.另外,还发现,在分离过程中使用氟化乙烯丙烯树脂(FEP)材质的Teflon烧杯作为收集流洗液的容器,能够在很大程度上提高237Np与233Pa的产额.α能谱、γ能谱以及分离纯化后的233Pa放置衰变曲线结果均表明,该方法可以将母体237Np与子体233Pa很好地分离开来,且所得到的233Pa溶液纯度高,可作为Pa元素的地球化学研究内标示踪剂.

Due to its fractionation from 230Th,231Pa is a powerful tool to unravel paleoceanographic information.As a solely isotopic spike for the determination of Pa yield during radiochemical procedure and 231Pa activity in geological samples,233Pa was usually produced by seperation from its parent nuclide,237Np.However,the conventional preparation method remained problematic to obtain highly purified 233Pa along with high recovery.With the purposing of preparing high-purified 233Pa,silica gel was used to separate 233Pafrom its parent nuclide,237Np.237Np went through the silica gel with 7 mol/L HNO3 solution,while 233Pa will remain in the silica gel without F-.The condition experiment with different concentrations of HF in the mixed 7 mol/L HNO3 ＋ HF solution indicated that 7 mol/L HNO3 ＋0.15 mol/L HF solution could elute off 233Pa from the silica gel with a high yield.In addition,FEP-type Teflon beakers could significantly increase the recovery of both 237Np and 233Pa during the separation.Such procedure could effectively separate 233pa from 237Np,and the results from α and γ spectrometer,as well as the decay curve of 233pa after the separation and purification demonstrated that three or three above passes through the silica gel column could help us obtain high-purified 233Pa available for the trace study in geochemistry of Pa.