title: Fully integrated glass microfluidic device for performing high-efficiency capillary electrophoresis and electrospray ionization mass spectrometry.
abstract: A microfabricated device has been developed in which electrospray ionization is performed directly from the corner of a rectangular glass microchip. The device allows highly efficient electrokinetically driven separations to be coupled directly to a mass spectrometer (MS) without the use of external pressure sources or the insertion of capillary spray tips. An electrokinetic-based hydraulic pump is integrated on the chip that directs eluting materials to the monolithically integrated spray tip. A positively charged surface coating, PolyE-323, is used to prevent surface interactions with peptides and proteins and to reverse the electroosmotic flow in the separation channel. The device has been used to perform microchip CE-MS analysis of peptides and proteins with efficiencies over 200,000 theoretical plates (1,000,000 plates/m). The sensitivity and stability of the microfabricated ESI source were found to be comparable to that of commercial pulled fused-silica capillary nanospray sources.
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapman Hall, Room 251, Chapel Hill, North Carolina 27599-3216, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Mellors
authors.forename: V
authors.initials: V
authors.lastname: Gorbounov
authors.forename: R S
authors.initials: RS
authors.lastname: Ramsey
authors.forename: J M
authors.initials: JM
authors.lastname: Ramsey
mesh_terms: D000327:Adsorption; D000818:Animals; D002417:Cattle; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D005898:Glass / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D010455:Peptides / Q000302:isolation & purification; D011506:Proteins / Q000302:isolation & purification; D040901:Proteomics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*; D013499:Surface Properties
chemical_list: D010455:Peptides; D011506:Proteins