研制了一种基于双毛细管的伸出型同轴鞘流毛细管电泳-电喷雾电离质谱（CE-ESI-MS）接口。通过设计不同的电路连接方式，实现自制接口与两台具有不同结构ESI源的质谱仪器的在线联用。此CE-ESI-MS系统可利用毛细管尖端电喷雾产生的负压作用完成流体动力进样，可实现皮升级微量样品的引入。此接口制作简单，成本低廉，死体积小。基于优化的缓冲液组成、鞘液流速和CE分离毛细管的伸出长度，系统可在长时间运行中保持稳定的电喷雾，质谱信号的相对标准偏差（RSD）为3.4%。对利血平样品的连续9次进样的保留时间、半峰宽、峰高、峰面积的重现性分别为1.9%、9.2%、16.9%和8.2%。在22 cm的有效分离长度内，此系统可在9 min内完成18种标准氨基酸的分离分析；在9 min内实现5种标准多肽混合物的基线分离，分离效率可达到7.27×10⁵ plates/m；对于细胞色素C的酶解产物，可在8 min内分离鉴定18种肽段。

A coaxial sheath-flow capillary electrophoresis-electrospray ionization mass spectrometry (CE-ESI-MS) interface based on dual capillaries was developed for performing rapid, efficient and sensitive analysis. By designing different electrode systems, the online combination between homemade interface and different ESI-MS systems was achieved. The CE-ESI-MS system utilized the suction effect to accomplish hydrodynamic injection without external force, and realized the introduction of picoliter samples. The interface had many advantages such as simple to build, low cost, good durability, minimal dead volume and low dilution effect based on optimized parameters. The spray stability was evaluated by continuous injection with a relative standard deviation (RSD) of 3.4%. Therefore, in the nine consecutive separations of reserpine, the RSD of retention time, full Width at Half Maximum and peak area were 1.9%, 9.2% and 8.2%, respectively. The present system was successfully applied to separate eighteen standard amino acids within 9 min. Moreover, the baseline separation of five standard peptides mixture was achieved within 9 min with the number of theoretical plates of 7.27×10⁵ plates/m. The present system also performed good performance in the analysis of cytochrome C trypsin digest.