Electrophoresis separation in open microchannels. A method for coupling electrophoresis with MALDI-MS

The separation of biological mixtures in open microchannels using electroph oresis with rapid and simple coupling to mass spectrometry is introduced. R apid open-access channel electrophoresis employs microchannels that are man ufactured on microchips. Separation. is performed in the open channels, and the chips are transferred to a matrix-assisted laser desorption/ionization (MALDI) source after the solvent is evaporated. The matrix (2,5-dihydroxyb enzoic acid) is placed in the solution with the run buffer before the separ ation of the analyte components, After separation, the solvent is evaporate d and the microchip is ready for MALDI-MS analysis. The microchip is placed directly into a specially designed ion source of an external source Fourie r transform mass spectrometry instrument. Separation of simple mixtures con taining oligosaccharides and peptides is shown.