毛细管电泳-电感耦合等离子质谱联用的接口设计

A Novel Interface for Coupling Capillary Electrophoresis with Inductively Coupled Plasma Mass Spectrometry

描述了毛细管电泳电感耦合等离子体质谱 (CE ICP MS)联用技术的单T型接口 ,自行设计了双T型接口 ,并对两接口的分析性能作了比较。解决了接口中的常见问题 ,使用节流阀减小自吸作用并降低了CE分离物的稀释倍数 ,排气阀使提升量保持稳定。经考察得知 ,采用自吸作用提升液流流量稳定 ,其重现性RSD小于 5 % ;双T型接口较单T型接口对CE分离更有利。采用双T型接口联用时 ,CE分离La、Ce、Nd混合离子迁移时间RSD小于 2 % ,MS信号RSD小于 15 % 。

A novel double-T interface for coupling capillary electrophoresis (CE) with inductively coupled phasma mass spectrometry (ICP-MS) was described, and its analytical performance was compared with that of a common single-T one. The double-T interface was characterized by flow-controlling valves that were used to minimize the suction effect and to avoid severe dilution of the analytes. And gas valves were adopted to obtain a more stable liquid flow. With utilizing the auto-aspirating effect of the nebulizer, a more stable flow rate was achieved, with RSD of 10 measurements being less than 5%. By comparison, it was concluded that the double-T interface was more preferable for CE separation than the single-T one through the separation and determination of Co and Zn ions. With the double-T interface, RSD of the CE migration time measurements was less than 2%, and RSD of the MS signal measurements was less than 15%. Moreover, the MS signal of analyte related linearly with its concentration when used the double-T interface to coupling CE separation with ICP-MS detection for the determination of simulated sample solution of La, Ce, Nd ions, which illustrated the practical application prospect of this novel interface.