BASIC AND APPLIED PROJECTS IN ANALYTICAL CHEMISTRY: I. THE DEVELOPMENT OF A SULFUR SPECIFIC DETECTOR FOR GAS CHROMATOGRAPHY BASED ON SULFUR DIOXIDE FLUORESCENCE. II. THE APPLICATION OF LASER RAMAN SPECTROMETRY FOR THE DETERMINATION OF QUARTZ AND CRISTOBA

This dissertation presents work on two different projects in analytical chemistry. These two projects are discussed in separate chapters of the dissertation.;Chapter I describes absorption and fluorescence studies performed on S(,2) and SO(,2), methods of generating these molecules from sulfur-containing compounds in a dynamic system, and finally, the coupling of dynamic conversion with fluorescence detection to form a gas phase sulfur specific detector for gas chromatography. The development of the gas phase fluorescence detector (GPFD) incorporated thermal oxidation of the reduced sulfur compounds and subsequent fluorescence detection of the resultant SO(,2) produced. The detector was found to have a minimum detectability of 10 ng S and a linear dynamic range of over two orders of magnitude. The performance characteristics of the GPFD, and the work leading to its development are discussed in Chapter I.;Chapter II describes the project wherein laser Raman spectrometry (LRS) was examined for its utility in the identification and quantification of crystalline silica polymorphs, quartz and cristobalite, in the inhalable fraction of Mount St. Helens volcanic ash. Unlike the X-ray diffraction and infrared spectra, the Raman spectra of these two polymorphs contain specific identification bands which are completely resolved from one another and from other bands due to the ash matrix. The LRS methodology developed exhibited a detectability in the 0.5 - 1.0 wt% range for quartz and cristobalite in the untreated ash matrix. The development of the LRS system for the reliable quantitative determination of solid samples and the LRS results obtained on the NIOSH round-robin ash samples are summarized.