【摘要】 建立了应用电感耦合等离子体质谱(ICP-MS)测定铀铌混合氧化物中痕量的稀土元素(Sm、Eu、Gd、Dy)的方法。这四种稀土元素在核燃料中的含量在10-7 g/g以下,但热中子截面很大,准确测定其在核燃料中的含量对于核燃料的研究至关重要。样品经HNO3-HF快速溶解后,应用CL-TBP萃淋树脂分离U基体,以115In作为测定内标校正基体干扰和仪器漂移,标准模式下应用ICP-MS定量测定淋洗液中Sm、Eu、Gd和Dy,半定量分析基体U。四种稀土元素的质量浓度为0.01~1.00μg/L,线性关系良好,线性相关系数(r)均大于0.999,检出限为0.001~0.002μg/L。对于添加0.2μg/L的稀土元素,稀土元素的回收率为84.3%~97.3%,相对标准偏差(sr)为5.3%~8.7%(n=6),能够满足实际样品测定需要。更多还原

【Abstract】 A method was developed for determination of trace rare earth elements(Sm,Eu,Gd and Dy)in U-Nb mixed oxide using inductively coupled plasma mass spectrometry(ICPMS).Though the contents of these four rare earth elements in nuclear fuel are below 10-7 g/g,the accurate determination of their contents in nuclear fuel is crucially important to the research of nuclear fuel for their thermal neutron-absorption cross-sections are large.After the sample was dissolved fast by HNO3-HF acids,U matrix was separated using CL-TBP extraction resin.115 In was used as internal standard to correct matrix interference and instrument drift for quantitative determination of Sm,Eu,Gd and Dy in eluate,semi-quantitative determination of U in eluate by ICP-MS.The method has a good linear correlation(r>0.999)in the range of 0.01-1.00μg/L and the detection limit is between 0.001-0.002μg/L.For the add concentrations of rare earth elements is 0.2μg/L,the recovery is between84.3%-97.3% and the relative standard deviation(sr)is between 5.3%-8.7%(n=6).The method can be available in practical application.更多还原