In this work, packed capillary liquid chromatographic separation methods including affinity chromatography have been developed and interfaced to an ion trap storage/reflectron time-of-flight mass spectrometer (IT/reTOF MS). The combination of the non-scanning property of the time-of-flight mass analyzer and the ion signal integration capability of the ion trap provide rapid and sensitive full-mass range detection. The use of capillary LC has been shown to provide a substantially improved detection limit over conventional LC. Also, the use of mass spectrometry detection in combination with capillary LC provided additional qualitative information by indicating the analyte molecular weight with its retention time and also increased the resolving power of this system by clearly identifying co-eluting components. This method was used in rapid identification of proteins in complex cell extracts and peptide mapping, in the location of protein post-translational modifications, in characterization of proteins in different bacterial species where bacteria can be differentiated to the species level, and in elucidation of the metabolism of therapeutic peptides without the necessity of radiolabels. The method developed herein has proved to be an effective and sensitive approach when analytes are present at low levels in complex biological systems and when it is difficult to isolate each target protein. The IT/reTOF MS has proved to be a rapid and sensitive mass detector for capillary separations of biological samples.Ph.D.Analytical chemistryPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/131584/2/9910034.pd
