Characterization of the resin bead and development and application of the porous ion emitter for thermal ionization mass spectrometry /by Matthew George Watrous.

To increase understanding of the resin bead ion source for mass spectrometry, lanthanide and actinide elements were studied as thermal ionization sources. Temperatures at which these ion sources gave maximum intensities were measured. The temperature trends correlate with the dissociation energies of the corresponding metal dicarbide. The metal dicarbide functions as a carrier to keep the lanthanide and actinides on the filament to higher temperatures. This results in release of the atomic species at a higher temperature where ionization probability is increased.;A new type of porous refractory material has been developed as a thermal ionization emitter that is an improvement over both direct filament and resin bead loading. Application of the porous ion emitter to uranium analysis is demonstrated to provide a utilization efficiency between 1 to 2% for a 0.2-10 pg sample; better than from resin beads or direct loading onto a filament.;The extent to which thermal ionization mass spectrometry (TIMS) can measure trace quantities of {esc}p233{esc}sU and {esc}p236{esc}sU in the presence of a huge excess of natural uranium was evaluated. The most favorable combination of sample loading and mass spectrometer is limited by the ability to generate a sufficiently intense ion beam to measure the minor isotopes above the detector background. The most favorable situations can measure isotope ratios in the range of 1 x 10{esc}p-10{esc}s. These are the triple sector mass spectrometer with a porous ion emitter and the single sector mass spectrometer with energy filtering.;The resin bead ion source has an increased efficiency for ion production as the mass of the element loaded decreases. Plutonium analysis from the porous ion emitter was attempted with many variations to improve the efficiency of ion production. The porous ion emitter did not top the resin bead for performance for plutonium.;The application of the resin beads and porous ion emitters is cross disciplinary to environmental, geological and the nuclear communities. The porous ion emitter is an improvement to the resin bead for ion production. The precise and accurate detection of ever-decreasing amounts of sample can be of benefit to these cross disciplinary applications.Thesis (Ph. D., Chemistry)--University of Idaho, July 2010