Decoupling CE and ESI for a more robust interface with MS
Decoupling CE and ESI for a more robust interface with MS
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DOI：
10.1002/elps.200900517
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发表时间：
2010-04-01
期刊：
影响因子：
2.9
通讯作者：
Chen, David D. Y.
中科院分区：
文献类型：
--
作者：
Maxwell, E. Jane;Zhong, Xuefei;Chen, David D. Y.
提出了一种 CE-ESI-MS 接口，可解耦分离和电离过程的电气和溶液流速要求。该接口使用围绕分离毛细管末端的锥形和斜面不锈钢空心针，以便电极内部充当 CE 出口小瓶，外部向上充当电喷雾发射器。无需对毛细管进行预处理，从而可以使用经过任何类型表面改性的毛细管。化学改性剂溶液通过第二个毛细管引入，该毛细管通过 T 形接头连接到针头，可用于提高 CE BGE 与电喷雾的兼容性。改性剂溶液的流速可低至 0 1 μL/min，远低于典型的鞘流界面中的流速，从而最大限度地减少 CE 流出液的稀释，从而最大限度地提高灵敏度。改性剂溶液的存在还允许使用中性涂层毛细管通过 CE-MS 进行蛋白质分析，而无需使用辅助压力，尽管在这些条件下不存在 EOF。该接口很容易集成到商业 CE 仪器中，以便所有操作都可以通过自动化控制进行。与在优化条件下运行的商用鞘流 CE-MS 接口相比，氨基酸的 LOD 平均提高了五倍
An interface for CE-ESI-MS that decouples both the electrical and the solution flow rate requirements of the separation and ionization processes is presented. The interface uses a tapered and beveled stainless steel hollow needle surrounding the separation capillary terminus so that the inside of the electrode acts as the CE outlet vial and the outside up acts as the electrospray emitter. No capillary pre-treatment is required, enabling the use of capillaries with any type of surface modification. A chemical modifier solution is Introduced through a second capillary connected to the needle via a tee)unction and can be used to improve the compatibility of the CE BGE with electrospray. The flow rate of modifier solution can be as low as 0 1 mu L/min, much less than that in a typical sheath-flow interface, thus minimizing dilution of the CE effluent in order to maximize sensitivity. The presence of the modifier solution also allows the use of neutral-coated capillaries for protein analysis by CE-MS without using an assisting pressure, despite the absence of EOF under these conditions The interface is easily integrated into a commercial CE instrument, such that all operations can be carried out by the automated controls. Compared with a commercial sheath-flow CE-MS interface operating under optimized conditions, LODs for amino acids were, on average, improved fivefold