Capillary electrophoresis-fourier transform ion cyclotron resonance mass spectrometry for the identification of cationic metabolites via a pH-mediated stacking-transient isotachophoretic method

Anal Chem. 2008 May 1;80(9):3112-22. doi: 10.1021/ac800007q. Epub 2008 Apr 3.

Abstract

Capillary electrophoresis-mass spectrometry (CE-MS) is still widely regarded as an emerging tool in the field of metabolomics and metabolite profiling. A major reason for this is a reported lack of sensitivity of CE-MS when compared to gas chromatography-mass spectrometry GC/MS and liquid chromatography-mass spectrometry. The problems caused by the lack of sensitivity are exacerbated when CE is coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), due to the relatively low data acquisition rate of FT-ICR MS. Here, we demonstrate the use of an online CE sample preconcentration method that uses a combination of pH-mediated stacking and transient isotachophoresis, coupled with FT-ICR MS to improve the overall detection of cationic metabolites in the bacterium Desulfovibrio vulgaris Hildenborough. This method showed a significant increase in signal-to-noise ratio when compared to CE normal sample stacking, while providing good separation efficiency, reproducibility, and linearity. Detection limits for selected amino acids were between 0.1 and 2 microM. Furthermore, FT-ICR MS detection consistently demonstrated good mass resolution and sub-ppm mass accuracy.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acids / analysis*
  • Bacteriological Techniques
  • Cations
  • Cyclotrons
  • Desulfovibrio vulgaris / chemistry*
  • Desulfovibrio vulgaris / metabolism*
  • Electrophoresis, Capillary / methods*
  • Fourier Analysis
  • Hydrogen-Ion Concentration
  • Mass Spectrometry / methods*

Substances

  • Amino Acids
  • Cations