title: Monolithic integration of two-dimensional liquid chromatography-capillary electrophoresis and electrospray ionization on a microfluidic device.
abstract: A microfluidic device capable of two-dimensional reversed-phase liquid chromatography-capillary electrophoresis with integrated electrospray ionization (LC-CE-ESI) for mass spectrometry (MS)-based proteomic applications is described. Traditional instrumentation was used for the LC sample injection and delivery of the LC mobile phase. The glass microfabricated device incorporated a sample-trapping region and an LC channel packed with reversed-phase particles. Rapid electrokinetic injections of the LC effluent into the CE dimension were performed at a cross-channel intersection. The CE separation channel terminated at a corner of the square device, which functioned as an integrated electrospray tip. In addition to LC-CE-ESI, this device was used for LC-ESI without any instrumental modifications. To evaluate the system, LC-MS and LC-CE-MS analyses of protein digests were performed and compared.
authors.affiliation: Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Chambers
authors.forename: J Scott
authors.initials: JS
authors.lastname: Mellors
authors.forename: W Hampton
authors.initials: WH
authors.lastname: Henley
authors.forename: J Michael
authors.initials: JM
authors.lastname: Ramsey
mesh_terms: D000818:Animals; D002417:Cattle; D056148:Chromatography, Reverse-Phase / Q000295:instrumentation / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D004926:Escherichia coli / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D010446:Peptide Fragments / Q000032:analysis; D012710:Serum Albumin, Bovine / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*
chemical_list: D010446:Peptide Fragments; D012710:Serum Albumin, Bovine