Ultra-high voltage capillary electrophoresis >300 kV: recent advances in instrumentation and analyte detection

Instrumentation has been developed for the implementation of ultra-high voltage capillary electrophoresis (UHVCE) with potentials up to and exceeding 300 kV. Several separations have been used to demonstrate the utility of higher applied voltages for improving the resolution of peptide, protein, and nucleic acid separations. Previously reported instrumentation was limited to 120 kV and required submersion in a bath of transformer oil to prevent corona and high voltage arcing between the components of the instrument [Hutterer, 1999, 2000, 2005] [1-3]. A modular design that uses plastic dielectric materials to overcome these obstacles enabling simplified operation of the instrument in air is described here in detail. A forced air system developed to control the temperature of the instrument to within a few degrees over a range of 25-60 °C for use with ultra-high voltage capillary gel electrophoresis is also described. UHVCE instrumentation and its applications with UV absorption and laser induced fluorescence detection are further developed, and the first demonstration of UHVCE coupled to electrospray ionization-mass spectrometry is shown.