title: Glass microfluidic devices with thin membrane voltage junctions for electrospray mass spectrometry.
abstract: In this study a novel glass membrane was prepared for conducting high voltage (HV) to solution in the channel of a microfabricated device for generation of liquid electrospray. Taylor cone formation and mass spectra obtained from this microdevice confirmed the utility of the glass membrane, but voltage conduction through the membrane could not be successfully explained based solely on the conductivity of the glass itself. This novel method for developing a high-voltage interface for microdevices avoids direct metal/liquid contact eliminating bubble formation in the channel due to water hydrolysis on the surface of the metal. Further, this arrangement produces no dead volume as is often found with traditional liquid junctions. At the same time, preliminary investigations into the outlet design of glass microdevices for interfacing with electrospray mass spectrometry, was explored. Both the exit shape and the use of hydrophobic coatings at the channel exit of the microdevice electrospray interface were evaluated using standard proteins with results indicating the utility of this type of design after further optimization.
authors.affiliation: Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, VA 22904, USA.
authors.forename: Guihua Eileen
authors.initials: GE
authors.lastname: Yue
authors.forename: Michael G
authors.initials: MG
authors.lastname: Roper
authors.forename: Erin D
authors.initials: ED
authors.lastname: Jeffery
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Easley
authors.forename: Catherine
authors.initials: C
authors.lastname: Balchunas
authors.forename: James P
authors.initials: JP
authors.lastname: Landers
authors.forename: Jerome P
authors.initials: JP
authors.lastname: Ferrance
mesh_terms: D004867:Equipment Design; D005898:Glass / Q000737:chemistry; D008567:Membranes, Artificial; D044085:Microfluidics / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation* / Q000379:methods; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D008567:Membranes, Artificial