A microfluidic glass chip for performing sensitive mass spectrometry (MS) is developed by integrating nanochannel-based electropreconcentration with electrospray ionization (ESI). Cation analytes in acidic buffer conditions (∼pH 3) were preconcentrated at a micro-nano-microchannel junction where a positively charged polymer, polyE-323, is coated to reverse the electroosmotic flows (anodic EOF) and prevent sample adsorption. The preconcentrated cation analytes were delivered to a monolithic spray tip using an integrated field-free electrokinetic pump, enabling a stable positive ESI with negligible dead volume. The sample preconcentration-ESI-MS achieved one order of magnitude signal enhancement in MS signal with a peptide mixture.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) ( NRF-2013M3A6A4046061 , NRF-2012-0009556 , and NRF-2011-0031866 ).
© 2018 Elsevier B.V.
- Electrospray ionization
- Ion concentration polarization
- Mass spectrometry
ASJC Scopus subject areas
- Analytical Chemistry
- Organic Chemistry