New studies and applications of ion chemistry in mass spectrometry

Research in gas-phase ion chemistry has been carried out from two slightly different approaches. The first approach is experimental in nature and consists of a detailed study of the methane and ammonia chemical ionization mass spectra of the phenothiazine compound class to produce a fundamental understanding of the energetics of the fragmentation pathways observed in the mass spectra of this class of compound under chemical ionization conditions, using a variety of reagent gases. Differences between the mass spectra so obtained are due to the effects of ion structure and ion internal energy.;The second approach combines the methods of modern computational chemistry with tandem mass spectrometry experiments to yield greater insight into the energetics, geometric structures, and electronic structures of gas-phase ions that contain one or more transition metal atoms. The ultimate goal of this research is to join theory and experiment in a method capable of the unambiguous identification of the structure of a given ion whose behavior in tandem mass spectrometry experiments is known.;Work in instrument development has involved the design and construction of a sophisticated data system to take full advantage of the analytical capabilities of a new imaging chromatography/SIMS instrument. The basic goal behind this work is development of a data system that will not only perform the nominal tasks expected from such a data system, but also provide the capability to perform sophisticated imaging experiments. The hardware and software aspects are discussed, and the system is evaluated in terms of the criteria initially set for the data system.