title: Simplified capillary electrophoresis nanospray sheath-flow interface for high efficiency and sensitive peptide analysis.
abstract: We report a simple nanospray sheath-flow interface for capillary electrophoresis. This interface relies on electrokinetic flow to drive both the separation and the electrospray; no mechanical pump is used for the sheath flow. This system was interfaced with an LCQ mass spectrometer. The best results were observed with a 2-microm diameter emitter tip and a 1-mm spacing between the separation capillary tip and the emitter tip. Under these conditions, mass detection limits (3sigma) of 100 amol were obtained for insulin receptor fragment 1142-1153. The separation efficiency exceeded 200,000 plates for this compound. The relative standard deviation generated during continual infusion of a 50 microM solution of angiotensin II was 2% for the total ion count and 3% for the extracted ion count over a 40-min period. Finally, the interface was also demonstrated for negative ion mode.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA.
authors.forename: Roza
authors.initials: R
authors.lastname: Wojcik
authors.forename: Oluwatosin O
authors.initials: OO
authors.lastname: Dada
authors.forename: Martin
authors.initials: M
authors.lastname: Sadilek
authors.forename: Norman J
authors.initials: NJ
authors.lastname: Dovichi
mesh_terms: D000804:Angiotensin II / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D016018:Least-Squares Analysis; D008956:Models, Chemical; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification; D011972:Receptor, Insulin / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods
chemical_list: D010455:Peptides; D000804:Angiotensin II; D011972:Receptor, Insulin