TY - JOUR T1 - On-column sample enrichment for capillary electrophoresis sheathless electrospray ionization mass spectrometry: evaluation for peptide analysis and protein identification. AU - Janini,George M, AU - Zhou,Ming, AU - Yu,Li-Rong, AU - Blonder,Josip, AU - Gignac,Michelle, AU - Conrads,Thomas P, AU - Issaq,Haleem J, AU - Veenstra,Timothy D, PY - 2003/11/1/pubmed PY - 2004/6/21/medline PY - 2003/11/1/entrez SP - 5984 EP - 93 JF - Analytical chemistry JO - Anal Chem VL - 75 IS - 21 N2 - 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. SN - 0003-2700 UR - https://www.unboundmedicine.com/medline/citation/14588041/On_column_sample_enrichment_for_capillary_electrophoresis_sheathless_electrospray_ionization_mass_spectrometry:_evaluation_for_peptide_analysis_and_protein_identification_ DB - PRIME DP - Unbound Medicine ER -