Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xxxvii, 419 p.; also includes graphics (some col.) Includes bibliographical references (p. 404-419). Available online via OhioLINK's ETD Center

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The application of Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) to the determination of total oxygen, nitrogen and sulphur in organic solution has been studied. Near-infrared emission lines of the three nonmetals have been used and detection limits in xylene have been established. Oxygen was determined for the first time by ICP-OES in a nongaseous sample. The characteristics of the inductively coupled plasma when used with an organic aerosol have been studied with respect to the completeness of atomization and potential interference from the complex excitation environment. Spatially resolved atomic and molecular emission profiles have been collected as part of these investigations. The nonmetal emission intensities were found to depend on the boiling point of the compounds containing the nonmetal because a redistribution effect in the nebulizer chamber was leading to an enrichment of volatile solutes in the aerosol stream to the plasma. Response factors for a series of compounds have been determined. The utility of the method was shown by establishing working curves and by testing certified standards for sulphur. / Science, Faculty of / Chemistry, Department of / Graduate

Experimental profiles of the He II lines at 3203 Å and 4686 Å have been obtained from a well diagnosed helium plasma. The plasma was produced in a low power z-pinch discharge contained in a vessel of 15 cm diameter and 60 cm length. Uniform plasma columns were located and studied by means of two moveable quartz limiter tubes. The effect of the tubes on the measured electron temperature and density due to cooling and evaporated impurities was measured and the tubes were positioned so as to select a uniform plasma column for study. Electron temperatures were determined from the intensity ratio of the lines He II 4686 and He I 5876 using a theory that considered finite escape probabilities for the Lyman a resonance photons. Electron densities were determined from the width of the He I 5876 line. Corrections were applied for ion broadening due to doubly charged ion perturbers. An electron temperature of 4.0±0.4 eV and an electron density of (6 .1 ±0.6) xl 0 2 3m"^;.wlere determined for the axial plasma occurring soon after the pinch phase. The experimental profile of He II 4686 as measured by a spectrometer-optical multichannel analyzer arrangement was compared to theoretical profiles resulting from a treatment of the electron broadening collisions as single event impacts (Kepple (1972)) and from a treatment of the electron broadening which considers the time development in the collision process (unified classical-path theory) (Greene (1976)). The experimental profile was found to lie midway between the theoretical profiles. Agreement between the experimental and unified classical-path profi1e in the near line wings was good. Agreement between experimental and electron impact results for He II 3203 was not good with a 60% disagreement in line widths. The He II line had a double peak with the peak at shorter wavelengths being 9% higher than the other peak. This is similar to the behavior observed in the Balmer line, Hβ, in the atomic hydrogen spectrum. / Science, Faculty of / Physics and Astronomy, Department of / Unknown

Rare earth elements, (REE), at ug g⁻¹ levels are used for studies of petrogenisis of different geological materials. For these studies, the REE must be determined precisely. An analytical program was established using an IL 200 Inductively Coupled Plasma, (ICP), spectrometer for the determination of the REE in various matrices, taking into consideration both matrix and spectral interferences, which were found to be severe in some cases. Dissolution of the sample, (0.4-1.0 g), was carried out using two methods; a microwave heated dissolution using a modified commercial microwave oven and a conventional oven heated closed pressure digestion vessel method. The results of these two methods were compared to determine the viability of using the more rapid microwave heated method. Separation of the REE from matrix elements was investigated using three cation exchange resins; Amber lite IR 120 (H), Zeocarb 225 and Dowex 50-WXS. A gradient acid elution method was established using a 15 cm by 20 mm Zeocarb 225 column. The sample was eluted with 140 ml of a 1.5 M H⁺ solution containing 0.75 M Cl⁻ and 0.75 M NO₃⁻, this fraction containing all the matrix elements. The REE were then eluted from the resin with 100 ml of 3 M HNO₃. The REE containing fraction was then reduced to 5 ml, diluted to 10 ml, and analysed for REE content. Liquid-liquid extraction methods for the separation of REE from matrix elements were investigated. It was found that the REE could be extracted synergistically from various buffered aqueous acidic media into chloroform, (CHCl₃), by hexafluoroacetylacetone, (HHFA), and quinoline. Acetylacetone, ( AcAc), was found to react with hexamethylenetetramine, (hexamine), when hexamine was used to buffer the aqueous phase during extraction procedures. The product of this reaction, 3.5-diacetyl-1.4-dihydro-2.6-dimethyl pyridine, was identified using X-ray crystallography.

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Thesis (Ph.D.)--Australian National University, 2004. / Errata slip inserted.

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Bibliography: leaves 161-163.

Thesis (doctoral)--Georg-August-Universität zu Göttingen, 1983. / Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 238-242).