碰撞池-多接收电感耦合等离子体质谱测定硒同位素的质量偏移效应  

Analysis of Mass Bias in Measurement of Selenium Isotope with Multicollectors Inductively Coupled Plasma Mass Spectrometry

作　　者：任同祥[1] 逯海[1] 王军[1] 贺欣宇[2] 周涛[1] 

机构地区：[1]中国计量科学研究院,北京100013 [2]北京化工大学,北京100029

出　　处：《分析化学》2010年第11期1620-1624,共5页Chinese Journal of Analytical Chemistry

基　　金：国家科技支撑计划项目(No.2006BAF06B07)资助

摘　　要：通过改变雾化气流量、RF射频发生器功率、矩管位置和碰撞气流量等仪器参数,研究了碰撞池-多接收电感耦合等离子体质谱(Collision Cell-MC-ICP-MS)中的质量偏移效应。实验结果表明,雾化气流量、RF发生器功率和矩管位置等是质量偏移效应的主要来源,而碰撞气流量的影响很小。在此基础上,建立了MC-ICP-MS分析硒同位素丰度的最优化测量条件,同位素比R82/76的测量精度达到0.0043%。采用化学计量方法配制了两个系列硒同位素丰度校正样品,通过不同的同位素丰度比的质量偏移校正因子β和与其对应的同位素对的质量平均值成线性的关系,分析了样品GBW(E)080215和SRM3149中硒的同位素丰度组成。与样品SRM3149中82Se/76Se的比值相比,样品GBW(E)080215中的硒同位素分馏系数δ82/76为-4.78‰。The source of mass bias in collision cell-multi-collectors inductively coupled plasma mass spectrometry （ MC-ICP-MS） was investigated by varying instrumental parameters. RF power and torch positions were proved to be the main sources caused mass bias,and the flow rate of collision gases had little influence on the isotope ratio. The optimized measurement conditions to analyze isotope ratios of selenium were developed, under these conditions,the precision of measured ratio R82/76 can reach to 0. 0043% . The isotopic composition of samples GBW（ E） 080215 and SRM3149 was analyzed with two selenium correction samples prepared by metrological method and based on the relationship that normalized mass bias factor was linear to the average atomic mass of the couple isotopes. Scaling to the value of R82/76 in sample SRM3149,the δ82/76 measured for GBW（ E） 080215 was 4. 78‰.

关 键 词：碰撞池-多接收电感耦合等离子体质谱 质量偏移 硒 同位素丰度 

分 类 号：O613.52[理学—无机化学]