悬浮进样-电感耦合等离子体质谱水溶液校正法测定高纯石墨中的超痕量硼  

Slurry Nebulization-Inductively Coupled Plasma Mass Spectrometry with Solution Calibration for Determination of Ultra-Trace Boron in High Pure Nuclear Graphite Powder

作　　者：刘欣丽[1] 段太成[1] 韩熠[1] 贾晓宇[1] 张伟娜[1,2] 陈杭亭[1] 

机构地区：[1]中国科学院长春应用化学研究所电分析化学国家重点实验室,长春130022 [2]吉林大学地球探测科学与技术学院,长春130026

出　　处：《分析化学》2010年第5期693-696,共4页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金(Nos.20605021;20975099)资助

摘　　要：建立了悬浮进样-电感耦合等离子体质谱(SN-ICP-MS)直接测定高纯核石墨中的超痕量硼的方法。石墨粉经过研磨和过筛后,粒径<5μm。选择聚乙烯吡咯烷酮(PVP)作为分散剂,石墨与分散剂优化的质量比(m/m)为0.5。通过磁力搅拌保证样品溶液的均一性与稳定性。以0.1mol/L氨水维持悬浮液(pH10)和消除硼的记忆效应。ICP-MS选择高分辨模式(0.6amu)消除基体12C的拖尾干扰。在等离子体中加入流量为60mL/min的氧气,以消除有机试剂对样品锥和截取锥产生的积碳影响,还可以加速样品粒子在等离子体中的解离。采用水溶液外标法定量,以Be为内标元素考察了对基体效应校正情况。本方法的线性范围为2～200μg/L,相关系数为0.9995,检出限为0.095μg/g。方法简单,快速,损失少。应用此法测定4个核石墨样品(纯度为99.999%),加标回收率为97.2%～103.1%,实验结果令人满意。The method of slurry nebulization-inductively coupled plasma mass spectrometry （SN-ICP-MS） was developed for the direct determination of trace boron in high purity graphite powders. The particle size was controlled 5 μm after the graphite powders was ground and sifted. Polyvinylpyrrolidone （PVP） was used as the dispersant in slurry preparation. The optimal mass ratio of PVP to the graphite was found to be 0.5. Well-proportioned and stable slurry solution was obtained by magnetic stirrer. About 0.1 mol/L NH4OH as the aqueous medium could provide the optimal pH of 10 for the stable slurry and eliminate the memory effect of B. ICP-MS was operated in a higher resolution mode （0.6 amu） to eliminate the interference with the matrix 12C by peak tailing. Oxygen was added into the plasma at a flow rate of 60 mL/min, to resolve carbon deposition on the sampler and skimmer cones and accelerate particle dissociation in the plasma. External calibration with aqueous solution standards was established for quantification. Beryllium was chosen as the internal standard to evaluate the efficiency of matrix effect correction. A correlation coefficient of 0.9995 for boron concentrations from 2 to 200 μg/L was obtained with a detection limit （3s） of 0.095 μg/g. As a practical application, with the advantage of simple, quick and low losing, the proposed method was applied to determine the trace boron in four nuclear graphite samples （claimed 99.999% purity）, with the satisfactory recoveries for the spike tests in the range of 97.2%-103.1%.

关 键 词：悬浮进样 电感耦合等离子体质谱 硼 高纯石墨 聚乙烯吡咯烷酮 

分 类 号：TQ127.11[化学工程—无机化工]