石墨探针进样-电感耦合等离子体质谱法测定强铀干扰下超微量^(240)Pu/^(239)Pu同位素比  

Isotopic Ratio of ^(240)Pu/^(239)Pu Measurements under Interference of Uranium by Inductively Coupled Plasma-Mass Spectrometry with Direct Sampling Insertion

作　　者：周国庆[1] 朱凤蓉[1] 李梅[1] 邓虎[1] 翟利华[1] 

机构地区：[1]西北核技术研究所,西安710024

出　　处：《分析化学》2011年第11期1682-1688,共7页Chinese Journal of Analytical Chemistry

摘　　要：采用自制的石墨探针直接进样装置(DSI)与电感耦合等离子体质谱(ICP-MS)联用进行了强铀干扰下超微量钚同位素比的分析技术研究。实验结果表明,由于DSI分析中存在显著的铀钚的分馏效应,可以实现分析中铀、钚的在线分离,从而降低了238U强峰对239Pu和240Pu分析的干扰。当样品中238U与239Pu的原子数之比超过105量级时,用DSI-ICP-MS方法测得的钚的同位素比结果与参考值的相对偏差小于1%,明显优于常规的ICP-MS分析方法。本方法可用于铀材料中超微量钚同位素比的分析,以在一定程度上降低对化学分离的要求,从而减小化学分离的难度和工作量。A self-made graphite probe direct sampling insertion device （DSI） with an inductively coupled plasma mass spectrometry （ICP-MS） was used to measure the isotopic ratios of 24^240pu/^239Pu under the interference of uranium. The interferences of ^238U to ^239pu and ^240 Pu were decreased because the uranium and plutonium in the sample could be separated on-line according to the evaporating discrimination on DSI of different element. The results of isotopic ratio obtained by DSI-ICP-MS are well consistent with the reference data and better than the results obtained by conventional solution nublizing sampling mode coupled with ICP-MS when the uranium is over 105 higher than the plutonium in the sample. The method of DSI-ICP-MS can be used in the isotopic ratio of plutonium measurement under the serious interference of uranium.

关 键 词：电感耦合等离子体质谱 直接进样装置 石墨探针 钚 铀 同位素比 

分 类 号：TL271.8[核科学技术—核燃料循环与材料]