Multiplexed Online-Monitoring of Microfluidic Free-Flow Electrophoresis via Mass Spectrometry

Free-flow electrophoresis is a tool for the continuous fractionation of electrically charged analytes. In this study we introduce a novel method to couple microchip-based free-flow electrophoresis with mass spectrometry. The successive connection of multiple microchip outlets to the electrospray ionization source of a mass spectrometer is automated using a multiposition valve. With this novel setup it is possible to continuously fractionate and collect compounds while simultaneously monitoring the process online with mass spectrometry. The functionality of the method is demonstrated by the successful separation and identification of the biomolecules AMP, ATP and CoA, which are fundamental for numerous biochemical processes in every organism.