5-Br-PADAP分光光度法测定钍中微量铀

SPECTROPHOTOMETRIG DETERMINATION OF MICRO AMOUNT OF URANIUM FROM THE LARGE AMOUNT OF THORIUM WITH 5-Br-PADAP

摘要: <正> 一、引言随着核能的发展,钍在核能中的应用正日益受到世界各国的重视。钍基核燃料辐照后转化为~(233)U,在后处理钍铂分离净化过程中需要测定常量钍存在下的微量铀。目前常量钍中铀的分析通常采用离子交换或TBP多次萃取-反萃分离,然后用分光光度法测定,但由于上
- 铀 /
- 钍 /
- DMHMP /
- 5-Br-PADAP /
- 分光光度法
Abstract: In this paper, the spectrophotometric determination of micro amount of uranium from the large amount of thorium with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) is investigated.Uranium is extracted from the large amount of thorium in 1 mol/1 HNO3 solution by di-(l-methylheptyl) methyl phosphate (DMHMP)in benzene. Then, the extracted uranium in organic phase (DMHMP) is determined directly by the spectrophotometric method with 5-Br-PADAP in ethanol medium. The apparent molar absorption of uranium at 575 nm is 7.0×104 1·mol-1·cm-1. Beer's law is obeyed within 10-60 μg of uranium in 25 ml solution.The precision of this method is within 1.0%. The recovery of uranium is over 98% (U=10-60μg) . The method is applied to the study in reprocessing of Th-U fuel. When concentration ratio of Th to U is lower than 2000, thorium doesn't influence the determination of uranium.
- U /
- Th /
- DMHMP /
- 5-Br-PADAP /
- Photospe ctrometry.

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