CAPILLARY ELECTROPHORESIS ELECTROSPRAY-IONIZATION ION-TRAP MASS-SPECTROMETRY USING A SHEATHLESS INTERFACE

The sensitivity that can be obtained with the quadrupole ion trap for on-line CE analysis using a sheathless electrospray interface and gold-tipped columns is examined. Capillaries of different i.d. are compared in continuous infusion experiments and the effects of sheath solvents on the signal for some peptides and proteins are illustrated. The sheathless CE/ITMS system using 20 mu m i.d. columns is shown to provide mid-attomole detection levels for leucine enkephalin in total ion electropherograms under full scan conditions. Good quality MS/MS spectra are also obtained for low femtomole injections of this peptide. (C) 1995 John Wiley & Sons, Inc.