磁质谱法测定高丰度稳定同位素样品中氙锗硼硅丰度  

Determination of abundance of xenon,germanium,boron and silicon in high abundance stable isotope samples by magnetic mass spectrometry

作　　者：曹金浩 杨凤诚[1] 侯超 刘佳龙 CAO Jinhao;YANG Fengcheng;HOU Chao;LIU Jialong(Research Institute of Physical and Chemical Engineering of Nuclear Industry,Science and Technology on Particle Transport Separation Laboratory,Tianjin 300180,China)

机构地区：[1]核工业理化工程研究院粒子输运与富集技术重点实验室,天津300180

出　　处：《冶金分析》2024年第5期47-53,共7页Metallurgical Analysis

摘　　要：高丰度气体同位素中丰度测定是离心法生产稳定同位素产品的重要环节。本研究采用改造的磁质谱仪,根据高丰度同位素样品氙气、四氟化锗、四氟化硅和三氟化硼电离后的谱图分析确定了各气体同位素丰度表征离子,并根据离子在磁场中的运动特征确定了法拉第杯及磁场位置,建立了一种高丰度气体稳定同位素样品(丰度大于99%)氙气、四氟化锗、四氟化硅和三氟化硼中氙、锗、硅和硼同位素丰度的质谱分析方法。测量结果表明,丰度最高的同位素为^(124)Xe(99.9554%),其相对标准偏差(RSD)为0.002%;四氟化锗中的^(76)Ge由天然丰度7.8%浓缩到了99.071%,各同位素测量结果的相对标准偏差均不大于1.6%,其中高丰度^(76)Ge为0.01%;四氟化硅中^(28)Si的丰度达到了99.9895%,各同位素丰度测量结果相对标准偏差均不大于1.4%;三氟化硼中^(11)B丰度达到99.9757%,^(10)B和^(11)B同位素丰度测量结果相对标准偏差最大为0.17%。在气体稳定同位素丰度检测过程中,增加反复抽空并测量的环境钝化步骤会有效降低记忆效应,尤其在高丰度稳定同位素检测过程中效果尤为明显。The determination of abundance in high abundance gas isotopes is an important step in the production of stable isotope products by centrifugation.In this study,a modified magnetic mass spectrometer was used to analyze the isotopic abundance characterization ions of each gas based on the spectra of xenon gas,germanium tetrafluoride,silicon tetrafluoride,and boron trifluoride after ionization in high abundance isotope samples.The Faraday cup and magnetic field positions were determined based on the motion characteristics of ions in the magnetic field.A mass spectrometry analysis method of isotopic abundance of xenon,germanium,silicon,and boron in high abundance gas stable isotope samples(abundance greater than 99%)xenon,of germanium tetrafluoride,silicon tetrafluoride,and boron trifluoride was established.The measurement results indicated that the isotope with the highest abundance was^(124)Xe(99.9554%),with a relative standard deviation(RSD)of 0.002%.The natural abundance of^(76)Ge in germanium tetrafluoride was concentrated from 7.8%to 99.071%,and the RSD of measurement result of each isotope was not greater than 1.6%(among them,the RSD of high abundance^(76)Ge was 0.01%).The abundance of 28Si in silicon tetrafluoride reached 99.9895%,and the RSD of measurement result of each isotope abundance was not greater than 1.4%.The abundance of^(11)B in boron trifluoride reached 99.9757%,and the maximum RSD of^(10)B and^(11)B isotope abundance measurements was 0.17%.During the detection of abundance of gas stable isotopes,the increase of environment passivation process could effectively reduce the memory effect,especially in the determination of high abundance stable isotopes.

关 键 词：高丰度 气体稳定同位素 质谱分析 氙 锗 硼 硅 

分 类 号：O657.63[理学—分析化学]