ONLINE CAPILLARY SEPARATIONS TANDEM MASS-SPECTROMETRY FOR PROTEIN DIGEST ANALYSIS BY USING AN ION-TRAP STORAGE REFLECTRON TIME-OF-FLIGHT MASS DETECTOR

Capillary separations interfaced to tandem mass spectrometry provide a very powerful tool for the characterization of biological macromolecu les such as proteins and peptides. The development of real time data-d ependent data acquisition has further enhanced the capability of this method. However, the application of this technique to fast capillary s eparations has been limited by the relatively slow spectral acquisitio n speed available on scanning mass spectrometers. in this work, an ion trap storage/reflectron time-of-flight mass spectrometer (IT/reTOF-MS ) has been used as an on-line tandem mass detector for capillary high- performance Liquid chromatography (HPLC) and capillary electrophoresis (CE) separations of peptide mixtures including a protein digest. By t aking advantage of the nonscanning property of the time-of-flight mass spectrometer, a fast spectral acquisition rate has been achieved. Thi s fast spectral acquisition rate, combined with a new protocol that sp eeds up tickle voltage optimization, has provided MS/MS spectra for mu ltiple components in a hemoglobin digest during one liquid chromatogra phy/mass spectrometry/mass spectrometry (LC/MS/MS) run. Further, the I T/reTOF-MS has the speed to provide MS/MS spectra for multiple compone nts in a CE separation of a synthetic peptide mixture within one CE/MS /MS run. (C) 1997 American Society for Mass Spectrometry.