Sheathless preconcentration-capillary zone electrophoresis-mass spectrometry applied to peptide analysis

A reliable capillary zone electrophoresis-electrospray ionization-tandem ma ss spectrometry system has been developed for the sensitive analysis and se quencing of peptides. The system comprises (1) a zero dead volume on-line s ample preconcentration interface allowing over 100-fold increase in sample volume introduction and (2) a zero-dead volume, durable electrospray emitte r yielding stable, low background electrospray signals, both proving not to compromize the electrophoretic performance. Sub-fmol sensitivities were ob tained in applications to complex peptide samples derived from tryptic dige stion of proteins and naturally processed major histocompatibility complex class I associated peptides. (C) 1999 American Society for Mass Spectrometr y.