二氧化铀芯块中微量Mn、Cr、Ni、Mo、Th的测定方法改进

Improve of Determination of Mn,Cr,Ni,Mo and Th in Uranium Dioxide Pallets

硝酸溶解二氧化铀芯块,采用TBP树脂连续分离Mn、Cr、Ni、Mo、Th五种元素,等离子体发射光谱(ICP-OES)法测定Mn、Cr、Th,石墨炉原子吸收(GAAS)法测定Ni、Mo。结果表明:3mol/L硝酸介质中,U、Th被TBP树脂吸附,Mn、Cr、Ni、Mo 4种元素直接进入接收液(A),继续用6 mol/L盐酸平衡柱子,弃去8mL死体积后,此时Th淋洗进入接收液(B)。接收液为高酸基体,元素浓度低,故将接收液蒸至近干,稀酸溶解测定。采用标准物质(GBW04242)对该方法进行验证,测定值均在标准值的置信区间内。

Uranium dioxide pallets were dissolved in HNO3.Mn,Cr,Th were determined by ICP-OES and Ni,Mo by GAAS after separation by TBP resins.U and Th were adsorbed in 3mol/L HNO3 by TBP resins and Mn,Ni,Mo,Cr were received as solution A.Th was received as solution B after 8mL dead volume.Solution A and B were steamed to nearly dry and then dissolve by dilute acid for measurement.The method is verified through reference material GBW04242.The measured values are in the confidence interval.