GEL-FILLED CAPILLARY ELECTROPHORESIS MASS-SPECTROMETRY USING A LIQUID JUNCTION ION SPRAY INTERFACE

This first report of on-line gel-filled capillary electrophoresis/mass spectrometry (CE/MS) and CE/MS coupled with tandem mass spectrometry demonstrates the feasibility of accomplishing this combination of analytical techniques. It is significant that this approach is feasible because of the considerable analytical potential for gel-filled capillary electrophoresis in the future. It is shown that relatively high concentrations of urea and other buffers required for achieving a separation in the gel do not elute from the gel and cause problems with mass spectrometric performance. The gel in the capillary effectively "decouples" the CE buffer from the mass spectrometric detection. In addition, the seperated analytes are successfully transported from the CE capillary through the liquid junction-ion spray interface and are detected by the mass spectrometer via electrospray ionization. These results, therefore, demonstrate the feasibility of gel-CE/MS for the separation and detection of organic anionic species of industrial and biological significance.