四氟化铀中钍等二十三种杂质元素的测定

Determination of Thorium i.e 23 Trace Elements in UF_4

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）。

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% H202 with a volume ratio 1 ： 1, then evaporated to dry repeatedly for the removal of F . By using a 415 mm× 105 mm CL-TBP column extraction chromatography, A1 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 （st） is better than 50%（n= 5） unless A1, Ca, Ba and Bi. In 6 mol/L HC1, 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 sr is within 5% （n=5）, and the detection limit of this separation method is 0. 037 μg/g UF4.