On-Column Sample Enrichment for Capillary Electrophoresis Sheathless Electrospray Ionization Mass Spectrometry: Evaluation for Peptide Analysis and Protein Identification
Although several designs have been advanced for coupling sample enrichment devices to a sheathless electrospray ionization-mass spectrometry (MS) interface on a capillary electrophoresis (CE) column, most of these approaches suffer from difficulties in fabrication, and the CE separation efficiency is degraded as a result of the presence of coupling sleeves. We have developed a design that offers significant improvements in terms of ease of fabrication, durability, and maintenance of the integrity of the CE-separated analyte zones. Capillaries with different inside and outside diameters were evaluated to optimize the performance of the CE-MS system, resulting in a mass limit of detection of 500 amol for tandem MS analysis of a standard peptide using a 20-microm-i.d. capillary. The improved design incorporates an efficient method to preconcentrate a sample directly within the CE capillary followed by its electrophoretic separation and detection using a true zero dead-volume sheathless CE-MS interface. Testing of this novel CE-MS system showed its ability to characterize proteomic samples such as protein digests, in-gel-digested proteins, and hydrophobic peptides as well as to quantitate ICAT-labeled peptides.
Amino acid sequence, apoproteins, bacteriorhodopsins, electrophoresis, capillary, hydrofluoric acid, isotope labeling, microscopy, electron, molecular weight, myoglobin, peptides, proteins, serum albumin, silicon dioxide, spectrometry, mass, electrospray ionization, trypsin
Janini, George M.; Zhou, Ming; Yu, Li-Rong; Blonder, Josip; Gignac, Michelle; Conrads, Thomas P.; Issaq, Haleem J.; and Veenstra, Timothy D., "On-Column Sample Enrichment for Capillary Electrophoresis Sheathless Electrospray Ionization Mass Spectrometry: Evaluation for Peptide Analysis and Protein Identification" (2003). Pharmaceutical Sciences Faculty Publications. 494.