Wu Yi-Ting, Chen Yu-Chie
Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan.
Anal Chem. 2005 Apr 1;77(7):2071-7. doi: 10.1021/ac048349i.
It has always been assumed that electrical contact at the capillary outlet is a necessary requirement when coupling capillary electrophoresis (CE) with electrospray ionization mass spectrometry (ESI-MS). In this study, we used a pulled bare-capillary tip as the ESI emitter, but neither was it coated with any electrically conductive materials nor was a high external voltage applied on its outlet. In this paper, we demonstrate that this straightforward approach may be used to generate multiply charged ions of proteins and peptides through electrospray ionization. Our results indicate that peptides and proteins, including bradykinin, cytochrome c, myoglobin, and tryptic digest products that elute from a pulled bare-capillary tip can be detected directly by ESI-MS using the tapered bare-capillary interface. Thus, we have demonstrated that CE and ESI-MS may be combined successfully without the need to modify the outlet of the capillary tip with an electrically contacting material.
一直以来，人们都认为在将毛细管电泳（CE）与电喷雾电离质谱（ESI-MS）联用的时候，毛细管出口处的电接触是一项必要条件。在本研究中，我们使用拉制的裸毛细管尖端作为电喷雾电离发射器，但既未在其上涂覆任何导电材料，也未在其出口施加高外部电压。在本文中，我们证明了这种直接的方法可用于通过电喷雾电离产生蛋白质和肽的多电荷离子。我们的结果表明，从拉制的裸毛细管尖端洗脱的肽和蛋白质，包括缓激肽、细胞色素c、肌红蛋白和胰蛋白酶消化产物，可使用锥形裸毛细管接口通过电喷雾电离质谱直接检测。因此，我们已经证明，毛细管电泳和电喷雾电离质谱可以成功联用，而无需用电接触材料对毛细管尖端出口进行修饰。
