| Abstract
| - Capillary electrophoresis−mass spectrometry (CE−MS)is still widely regarded as an emerging tool in the field ofmetabolomics and metabolite profiling. A major reasonfor this is a reported lack of sensitivity of CE−MS whencompared to gas chromatography−mass spectrometryGC/MS and liquid chromatography−mass spectrometry.The problems caused by the lack of sensitivity areexacerbated when CE is coupled to Fourier transform ioncyclotron resonance mass spectrometry (FT-ICR MS), dueto the relatively low data acquisition rate of FT-ICR MS.Here, we demonstrate the use of an online CE samplepreconcentration method that uses a combination of pH-mediated stacking and transient isotachophoresis, coupledwith FT-ICR MS to improve the overall detection ofcationic metabolites in the bacterium Desulfovibrio vulgaris Hildenborough. This method showed a significantincrease in signal-to-noise ratio when compared to CEnormal sample stacking, while providing good separationefficiency, reproducibility, and linearity. Detection limitsfor selected amino acids were between 0.1 and 2 μM.Furthermore, FT-ICR MS detection consistently demonstrated good mass resolution and sub-ppm mass accuracy.
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