四氟化铀中钍等二十三种杂质元素的测定

本工作采用体积比1∶1浓硝酸和过氧化氢(φ=30%)加热溶解四氟化铀(UF4)后,再用浓硝酸或浓盐酸反复溶解蒸干,去除氟离子。在3mol/L硝酸介质中,采用15mm×105mm CL-TBP萃淋树脂柱分离铀中杂质,收集第6—15mL淋洗液,用等离子体发射光谱法(ICP-AES)进行测量。Al等22种元素回收率在97%~113%之间,除Al、Ca、Ba和Bi外其它元素相对标准偏差在5%以内(n=5)。在6mol/L盐酸介质中采用15mm×105mm CL-TBP萃淋树脂柱分离铀中Th,进行ICP-MS测量。Th回收率在91%~94%之间,相对标准偏差在5%以内(n=5),分析方法的检测下限为0.037μg/g(以UF4计)。

Determination of Thorium i.e 23 Trace Elements in UF4

A method for determination of thorium i.e 23 trace elements in UF₄ is established. In this work, UF₄ was dissolved by HNO₃ and φ=30% H₂O₂ with a volume ratio 1∶1, then evaporated to dry repeatedly for the removal of F^-. By using a 15 mm×105 mm CL-TBP column extraction chromatography, Al i.e 22 trace elements were separated with uranium in 3 mol/L HNO₃, the sixth to fifteenth mL eluent were collected for determination by ICP-AES. The recovery of these elements is between 97%-113%, and the relative standard deviation (s_r) is better than 5%(n=5) unless Al, Ca, Ba and Bi. In 6 mol/L HCl, the uranium was separated by TBP levextred resin chromatography, and the thorium was determined by ICP-MS. The recovery of Th is between 91%-94%, and the s_r is within 5% (n=5), and the detection limit of this separation method is 0.037 μg/g UF₄.