Time-of-flight mass spectrometers are low cost instruments with high mass range and sensitivity. In recent years methods have been developed for improving their mass resolution. Improvements in high speed data acquisition are expected to lead to their development as """"""""ideal"""""""" chromatographic detectors, with duty cycles (and hence sensitivity and chromatographic resolution) superior to scanning methods. The liquid secondary ion time-of- flight mass spectrometer (liquid-SIMS-TOF), developed in this project, brings fast atom bombardment (high flux primary beams and solution chemistry) to the TOF analyzer. During the proposed period, time-delayed ion extraction will be exploited for time (mass) focussing of metastable ions, which contribute to the baseline in linear TOF instruments and are filtered out by reflection or other energy focussing devices. In a unique configuration, employing both time-lag focussing and ion reflection, resolving power for both prompt and metastable ions will be improved. A continuous flow probe will be developed as an interface to a high pressure liquid chromatograph, using high duty cycle data acquisition. Long term objectives are to develop an approach with high mass range, high mass and chromatographic resolution, and high sensitivity, which provides an alternative to collisionally induced dissociation for enhancement of structural information. This approach will improve our understanding of the influence of secondary and tertiary structure on fragmentation of biomolecular ions and provide structural analyses of mixed bipolymers:glycopeptides, phosphopeptides, glycolipids and phospholipids. Such information will provide rapid indentification of bacteria from whole cells; and elucidate the effect of growth temperature on the composition of polar lipids; relationships between structure, toxicity and immunogenicity in bacterial lipopolysaccharides; sites of glycosylation, phosphorylation and other post-translational modifications in peptide processing; oxidation, dimerization and other degradation products in preparations of insulin, human atrial natriation factor (hANF) and epidermal growth factors, in ongoing projects of the mass spectrometry factility.
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