Open AccessFully Integrated Glass Microfluidic Device for Performing High-Efficiency Capillary Electrophoresis and Electrospray Ionization Mass Spectrometry
Author(s) -
J. Scott Mellors,
V. Gorbounov,
Roswitha S. Ramsey,
J. Michael Ramsey
Publication year - 2008
Publication title -
analytical chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.117
H-Index - 332
eISSN - 1520-6882
pISSN - 0003-2700
DOI - 10.1021/ac800428w
Subject(s) - chemistry , electrokinetic phenomena , electrospray , capillary electrophoresis , capillary action , mass spectrometry , microfluidics , chromatography , electrospray ionization , analytical chemistry (journal) , electrophoresis , capillary electrophoresis–mass spectrometry , coating , nanotechnology , materials science , composite material , organic chemistry
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.