Development of charge reduction electrospray mass spectrometry for biopolymer and synthetic polymer analysis

This dissertation describes the work involved in the development of mass spectrometry as a tool for analysis of large polymers. Instrumental advancements to Charge Reduction Electrospray Ionization Mass Spectrometry (CREMS) are described, and various applications of this technique are explored. Charge reduction (reducing the charge states of analyte ions generated by the electrospray process) had previously been achieved by employing the radioactive isotope 210Po to produce neutralizing species. This dissertation reports on the application of corona discharge to CREMS for the analysis of complex mixtures of biological molecules. This technique provides charge reduction for the simplification of ESI spectra without need for any radioactive material. To improve sensitivity and versatility, a capacitive charging electrospray source has been developed. Capacitive charging results in the production of a linear stream of charged droplets when an aqueous solution is pumped through the capillary. Subsequent solvent evaporation yields ions, providing a continuous ion source for mass spectrometry.;These instrumental advancements provide the groundwork for analysis of DNA sequencing reactions by Electrospray Ionization Mass Spectrometry. Sequencing reactions must be performed in a manner to provide sufficient analyte for analysis by mass spectrometry. Presently, the purification and analyte abundances necessary for these analytical methods do not allow for cost effective large-scale analysis. In addition, a signal intensity fall-off with increasing mass of DNA strand continues to be evident with this technology, thereby limiting the read length in DNA sequence analysis.;The application of Corona discharge CREMS to synthetic polymers is next investigated. The charge on commercially available poly(ethylene glycol) samples is reduced to create singly charged ions that are then analyzed by a time-of-flight mass spectrometer. It is shown that the charge reduction process, by eliminating the multiple charging effects of conventional ESI analysis, makes possible the determination of polymer size distributions.