Doctor of Philosophy, Miami University, 2012, Chemistry and Biochemistry

This dissertation contains six chapters demonstrating the use of Terahertz Time-Domain spectroscopy and imaging in a variety of applications, from the principle analysis of observed absorption features to the quantitation of threat agents. Chapter 1 focuses on the background of Terahertz, starting with its roots in Microwave and Infrared Spectroscopies and continuing on to modern time-domain techniques that dominate the field at present. Terahertz's interaction with different types of matter, various instrumentation setups, and several types of common time-domain measurements are also discussed. Chapter 2 discusses two separate studies attempting to further the understanding of collective mode absorption peaks observed in the THz spectral region. Absorption peaks found in the THz region of crystalline solids are typically described generically as collective modes or computationally analyzed with no supporting experimental data. These two studies demonstrate an experimental method that can be used concurrently with computational techniques to elucidate a more complete understanding of observed collective modes. Chapter 3 probes the feasibility of detecting a possible threat agent, dipicolinic acid, which is a major component in bacterial spores, such as Anthrax. It focuses on qualitative discovery and the ability to quantify its presence with Terahertz Spectroscopy and imaging. Chapter 4 presents a library of quality cryogenic and room temperature spectra for the 20 standard amino acids to be used as a reference for future research. In addition, trends observed by the groups of amino acids were assessed. Chapter 5 examines the spectral properties of a large biomolecule, heparin, in the terahertz spectral region. Several sample configurations are investigated, from heparin as-is to crystallized nitric acid digestion remnants. A novel trace metal analysis method of heparin utilizing Inductively Coupled Plasma Optical Emission Spectroscopy is also presented. Chapter 6 d (open full item for complete abstract)

Committee: Gilbert E. Pacey PhD (Advisor); Shouzhong Zou PhD (Committee Chair); Richard T. Taylor PhD (Advisor); C. Scott Hartley PhD (Committee Member); James R. Gord PhD (Committee Member) Subjects: Analytical Chemistry