Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638196
Title: Applications of mass spectrometry in physical, organic and inorganic chemistry
Author: Milton, D. M. P.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1991
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Abstract:
Proton transfer reactions to monosubstituted benzenes have been studied in the gas phase as a function of protonation exothermicity using tandem mass spectrometry. The results have been interpreted in terms of competitive ring and substituent protonation and intramolecular proton migration with the aid of molecular orbital calculations. It is shown that during the reaction of CHs+ with fluorobenzene at temperatures less than 330K, proton transfer occurs preferentially to the F atom even though its proton affinity is approximately 180kJmol-1 less than the ring. Samples of ruthenium dioxide hydrate have been studied using the technique of mass spectral thermal analysis, before and after thermal activation. Two types of chemically bound water are identified, of which the loss of one is associated with the thermal activation. Headspace analysis of isotopically enriched gases evolved during reactions of these two forms indicates that the decomposition products contain oxygen atoms originating from the solvent. A glow discharge ion source has been constructed to fit an MS9 mass spectrometer. This source has been demonstrated to compare well with previous configurations for the analysis of metals in pin form. Fundamental studies show that the majority of the sputtering flux is observed to possess low energies, due to de-energising symmetrical charge transfer reactions in the cathode dark space. Ions of the cathode material possess higher energies, and it appears that sputtering of the cathode is mainly caused by atoms of the cathode material itself. Analysis of solutions has been performed using the flow discharge ion source. Lead and platinum were monitored at the ppb level in the urine of patients receiving cancer chemotherapy with the drug cis-platin. The data obtained support the idea that normally stored body lead is displaced by the platinum complexed in the drug, but only to a small extent. A novel investigation was made into the suitability of the technique for the analysis of organic species deposited on the cathode. The spectra of a wide variety of compounds are very similar to desorption chemical ionisation spectra. Although some sputtering does occur, the principal desorption process appears to be caused by rapid localised heating at the cathode surface.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.638196  DOI: Not available
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