Instrument Development and Application for Qualitative and Quantitative Sample Analyses Using Infrared and Raman Spectroscopies

This dissertation describes the development and application of methods and instrumentation for qualitative and quantitative sample analyses by infrared and Raman spectroscopies. An introduction to the concepts and methods utilized is provided in Chapter 1. A comparative evaluation of solid-core silver halide fiber optics and hollow silica waveguides was performed on the basis of the transmission of mid-infrared radiation using a fiber optic coupling accessory and an infrared microscope is presented in Chapter 2. Increased transmission was reproducibly observed between two identical hollow waveguides due to minimization of insertion and scattering losses resulting from the hollow core. Chapter 3 presents an evaluation of a mid-infrared, attenuated total (internal) reflection (ATR) probe accessory utilizing hollow waveguides based on transmission and signal-to-noise. Quantitative analyses of aqueous succinylcholine chloride and ethanol solutions were also performed. An in situ Raman study of nitrogen incorporation in thin films of zinc oxide using a temperature-controlled reaction cell is discussed in Chapter 4. Monitoring nitrogen incorporation in thin films of zinc oxide at elevated temperatures in the presence of nitrogen-containing precursor reagents proved inconclusive using the proposed method. Chapter 5 presents an evaluation of dispersive and Fourier transform (FT-) Raman spectroscopies for on-line process control in the bottling industry. FT-Raman was determined to be more applicable for on-line determinations of poly(ethylene terephthalate) bottle thickness due to the availabilities of such benefits as increased laser power and fluorescence rejection. Preliminary data from the development of an inverted ATR imaging microscope are discussed in Chapter 6. The inverted optical design of the microscope permits simultaneous viewing of the sample with white light and the collection of infrared spectral images. Summaries of the presented research are provided in Chapter 7.