SEM-ICP-MS测定单微粒铀同位素比值

Determination of Single Uranium Particle Isotope Ratio by SEM-ICP-MS

摘要: 将扫描电镜(SEM)与多接收电感耦合等离子质谱(MC-ICP-MS)联用，建立了新的测定单微粒铀同位素比值的分析方法。通过使用SEM上的能量色散X射线荧光光谱（EDX）寻找、鉴别含铀微粒，利用微操作器进行单个微粒的转移，经化学溶解后用MC-ICP-MS测定同位素比值。本工作以CRM U850、U350、U005-A三种丰度不同粒径的铀微粒为测量对象。各种丰度微粒的形貌存在较大差异，同位素比值测定结果与标称值一致，相对标准偏差(s_r)最大分别在3.3%、2.2%和4.6%以内。

Abstract: A new method was developed for the determination of single uranium particle isotope ratio by using multi-collector ICP-MS (MC-ICP-MS) combined with scanning electron microscope (SEM). The single uranium particle was searched and located by SEM and identified by EDX, then transferred by micromanipulator. The isotope ratio was measured by MC-ICP-MS after chemical dissolution. CRM U850, U350 and U005-A uranium particles with different diameter were analyzed. The particles with different enrichment have different morphology. The isotope ratio results consist with the certified values and s_r is within 3.3%, 2.2% and 4.6% separately.