质谱同位素稀释法测定U_3O_8标样中痕量Th

The Determination of Trace Thorium in Standard Sample of U_3O_8 by Isotope Dilution Mass Spectrometry (IDMS)

以^(230)Th作稀释剂用IDMS测定了U_3O_8标样中痕量Th。取样1g,先在9mol/l HCI体系中用阴离子交换法除去大量U及Fe、Pb等杂质,进而以CL5209型萃淋树脂分离Th。本法测Th的检出限为2.4×10^(-9)g。分析含Th 0.873 ppm 的U_3O_3试样时方法的精密度为±3.3%。

Standard sample of U_3O_?e is spiked with ^(230)Th, a great quantity of U and trace amounts of Fe,Pb, Cr, V, Ti and W thus obtained are removed by anion ion-exchange resin. Then the thoriumis separated from residual U and other elements on an extractant-containing resin column of CL5209. The detection limit and precision of the method are 1.3×10^(-?)gTh and ±3.3% respecti-vely.