title: Characterization of the microdialysis junction interface for capillary electrophoresis/microelectrospray ionization mass spectrometry.
abstract: A capillary electrophoresis/electrospray ionization mass spectrometry (CE/ESI-MS) interface, based on an electric circuit across a microdialysis membrane surrounding a short capillary segment closely connected to the separation capillary terminus, is demonstrated to be sensitive, efficient, and rugged. A microspray type ionization emitter produces a stable electrospray at the low flow rates provided by CE and thus avoids both the need for a makeup liquid flow provided by liquid junction or sheath flow interfaces and the subsequent dilution and reduction in sensitivity. Reproducibility studies and comparisons with CE/UV and the CE/sheath flow interface with ESI-MS are presented. Additionally, postrun acidification via the microdialysis junction interface is demonstrated and shown to be capable of denaturing the holomyoglobin protein noncovalent complex while maintaining separation efficiency.
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Box 999, Richland, Washington 99352.
authors.forename: J C
authors.initials: JC
authors.lastname: Severs
authors.forename: R D
authors.initials: RD
authors.lastname: Smith