Department of Chemistry, Aalen University, Aalen, Germany.
Instrumental Analytical Chemistry and Centre for Water and Environmental Research (ZWU), Universitätsstraße, University of Duisburg-Essen, Essen, Germany.
Electrophoresis. 2021 Feb;42(4):369-373. doi: 10.1002/elps.202000169. Epub 2020 Aug 19.
CE hyphenated to ESI-MS (CE-ESI-MS) is a well-established technique to analyze charged analytes in complex samples. Although various interfaces for CE-MS coupling are commercially available, the development of alternatives which combine sensitivity, simplicity, and robustness remains a topic of research. In this work, a nanoflow sheath liquid CE-MS interface with two movable capillaries inside a glass emitter is described. The setup enables a separation mode and a conditioning mode to guide the separation capillary effluent either into the electrospray or to the waste, respectively. This enables to exclude parts of the analysis from MS detection and unwanted matrix components reaching the mass spectrometer, comparable to divert valves in LC-MS coupling. Also, this function improves the overall robustness of the system by reduction of particles blocking the emitter. Preconditioning with electrospray interfering substances and even the application of coating materials for every analysis is enabled, even while the separation capillary is built into the interface with running electrospray. The functionality is demonstrated by analyses of heavy matrix bioreactor samples. Overall, this innovation offers a more convenient installation of the interface, improved handling with an extended lifetime of the emitter tips and additional functions compared to previous approaches, while keeping the higher sensitivity of nanoflow CE-MS-coupling.
CE 与 ESI-MS 联用（CE-ESI-MS）是分析复杂样品中带电分析物的一种成熟技术。虽然各种 CE-MS 接口在商业上都有供应，但开发具有灵敏度、简单性和鲁棒性的替代方案仍然是一个研究课题。在这项工作中，描述了一种带有两个可移动毛细管的纳流鞘液 CE-MS 接口，该接口位于玻璃喷管内。该设置可实现分离模式和调节模式，分别将分离毛细管的流出物引导至电喷雾或废物中。这使得可以排除 MS 检测中的部分分析物和进入质谱仪的不需要的基质成分，类似于 LC-MS 联用中的分流阀。此外，该功能通过减少堵塞喷管的颗粒来提高系统的整体鲁棒性。即使在分离毛细管与运行的电喷雾一起安装在接口中，也可以进行电喷雾干扰物质的预调节，甚至可以对每种分析应用涂层材料。通过对生物反应器中重基质样品的分析证明了该功能。总的来说，与以前的方法相比，这项创新提供了更方便的接口安装、更便捷的操作、更长的喷管尖端寿命和额外的功能，同时保持了纳流 CE-MS 联用的更高灵敏度。
