Graduation date: 1990

Thesis (Ph. D.)--University of Washington, 1988. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--Washington State University, December 2006. / Includes bibliographical references.

An instrument is described which is capable of measuring the action spectrum of the removal of CO inhibition of respiration by light. In the method employed here, a cell suspension in a CO-O₂ atmosphere is alternately exposed to two wavelengths of light. Their photochemical effects are balanced using an 0₂ electrode as the null detector. The light intensities at the balance points from a series of wavelength pairs are used to determine the ratios of the extinction coefficients of the CO - oxidase complex, at the various wavelengths, to the extinction coefficient at a standard wavelength. An action spectrum for Bakers yeast is shown. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Experiments were designed for an undergraduate instrumental analysis laboratory course, two in X-ray diffraction and two in electrochemistry. Those techniques were chosen due their underrepresentation in the Journal of Chemical Education. Paint samples (experiment 1) and pennies (experiment 2) were characterized using x-ray diffraction to teach students how to identify different metals and compounds in a sample. in the third experiment, copper from a penny was used to perform stripping analyses at different deposition times. As the deposition time increases, the current of the stripping peak also increases. the area under the stripping peak gives the number of coulombs passed, which allows students to calculate the mass of copper deposited on the electrode surface. the fourth experiment was on the effects of variable scan rates on a chemical system. This type of experiment gives valuable mechanistic information about the chemical system being studied.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

A direct injection nebulizer was constructed in our laboratory and was evaluated as an interface between a liquid chromatography column and an inductively coupled plasma-atomic emission spectrometer (ICP-AES). Optimum operating conditions, detection limits, and reproducibility in water and in organic solvents were studied. The detection limits in water were similar to a commercially available device. The detection limits of elements in organic solvents were about ten times higher than those in water. The DIN-ICP system stave more uniform response towards different species of Phosphorus and osmium than did a Meinhard nebulizer-ICP system, even when great differences in volatilitN existed between the species. A Potential application to the speciation of cisplatin and its analogs was also investigated. / Department of Chemistry

Orientadores: Maria Izabel Maretti Silveira Bueno, Andre Messias Krell Pedro / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T07:47:54Z (GMT). No. of bitstreams: 1 Oliveira_Lidianede_D.pdf: 1707192 bytes, checksum: 2d18bc899e66ae89668afb1e436f23b3 (MD5) Previous issue date: 2014 / Resumo: Tem por objetivo o desenvolvimento de um método empregando técnicas analíticas instrumentais (Microextração em Fase Sólida por Headspace e Cromatografia Gasosa acoplada à Espectrometria de Massas (HS-SPME-GC-MS), Espectroscopia de Fluorescência de Raios-X e Espectroscopia no Infravermelho Próximo) aliadas ao método quimiométrico MASLT (Multivariate Accelerated Shelf-Life Test) para análise de perda de fragrância em sabonetes em barra, visando acelerar a obtenção dos dados necessários para a determinação do prazo de validade desse tipo de produto. As amostras analisadas foram sabonetes em barra contendo 1,2% (m/m) de uma fragrância de composição conhecida e os resultados instrumentais foram validados com a avaliação sensorial realizada por um painel treinado, método de análise convencional para esse tipo de estudo. As técnicas de HS-SPME-GC-MS possibilitaram que dados originários de instrumentação analítica fossem utilizados diretamente para o estudo das propriedades de interesse e determinação do prazo de validade do produto, permitindo a realização de estudos mais rápidos e robustos, não baseados apenas em respostas subjetivas oriundas de painéis sensoriais. Além disso, o prazo de validade calculado a partir desses dados concordou com aquele determinado sensorialmente, sendo essa a técnica mais indicada para a aplicação em questão. As outras duas técnicas avaliadas (Espectroscopia de Fluorescência de Raios-X e Espectroscopia no Infravermelho Próximo) se mostraram pouco adequadas para o objetivo proposto, visto que os dados obtidos apresentaram grande interferência de outras variações ocorridas nas amostras (perda de umidade, alterações na apresentação da amostra, mudanças na microestrutura do produto, etc.), não refletindo somente a perda de fragrância / Abstract: Aims at developing a method combining instrumental analytical techniques (Headspace ¿ Solid Phase Micro-Extraction ¿ Gas Chromatography ¿ Mass Spectrometry (HS-SPME-GC-MS), X-Ray Spectroscopy and Near Infrared Spectroscopy) and the chemometrics method MASLT (Multivariate Accelerated Shelf-Life Test) for analysis of fragrance loss in toilet soap bar, with the objective of accelerating the data acquisition for determining the shelf-life of this kind of product. The samples consisted of toiled soap bars containing 1.2% (w/w) of a fragrance of well-known composition and instrumental results were validated through sensory analyses performed by a trained panel, standard method for shelf-life studies in case of toilet soap bar. The analytical techniques HS-SPME-GC-MS enabled the direct application of instrumental analytical data for studying the properties of interest and the determination of the shelf-life of the product, allowing faster and more robust studies, not based only on subjective results from sensory panels. Moreover, the shelf-life determined in this case agreed with one determined by the sensory panel, making it the most adequate technique for the application proposed. The other two techniques evaluated were less adequate to the objective proposed, since the data was interfered by other sample modifications (moisture loss, presentation of the sample, microstructure modifications, etc.) and not only by the fragrance loss / Doutorado / Quimica Analitica / Doutora em Ciências

Daktaro disertacijoje tirta hidroterminės sintezės sąlygų, žaliavų prigimties ir priedų įtaką hidrotalcito susidarymui ir savybėms bei pasiūlytos racionalios jo taikymo sritys. Nustatyta, kad lemiamą įtaką hidroterminės hidrotalcito sintezės eigai turi Mg turinčio komponento atmaina ir hidroterminio apdorojimo sąlygos. Palankiausios šio junginio hidroterminės sintezės sąlygos Mg5(CO3)4(OH)24H2O ir -Al2O3 mišiniuose yra: izoterminio išlaikymo temperatūra – 200 °C, trukmė – 1 h, o Mg/Al molinis santykis žaliavų mišinyje yra du. Ištirta, kad NaOH ir KOH priedai pradiniuose mišiniuose skatina ne tik žaliavų sąveiką, bet ir keičia hidroterminės sintezės metu susidarančių junginių seką mažindami hidrotalcito susidarymo temperatūrą ir/ar sutrumpindami jos trukmę. Nustatyta, kad keičiant modifikuotų hidrotalcitų cheminę sudėtį galima kontroliuoti mišrių metalų oksidų ir jų nanodarinių kietafazio sukepimo sąlygas bei produktų paviršiaus mikrostruktūros parametrus. Ištirta, kad chemosorbcijos metodas yra tinkamas aktyviųjų komponentų – pereinamųjų metalų jonų imobilizavimui iš jų druskų tirpalų į sintetinius hidrotalcitus. Nustatyta ir kinetiniais skaičiavimais patvirtinta, kad pastariesiems būdingos pakaitų reakcijos yra negrįžtamos, t. y. beveik visi Zn2+, Ni2+, Co2+, Mn2+ ir Fe3+ jonai buvo adsorbuoti pagal cheminę sąveiką. Nustatyta, kad hidroterminės sintezės metodas yra tinkamas hidrotalcito sluoksnio formavimui ant Al/Al2O3 paviršių. / In PhD thesis, the influence of synthesis conditions, the chemical nature of raw materials and additives on the crystallization processes of hydrotalcite and its properties were examined and expedient areas of hydrotalcite application were proposed. It was determined that the modification of Mg containing coumpound as well as the hydrothermal synthesis conditions have a significant infuence on the course of hydrotalcite formation. The optimal conditions of hydrotalcite hydrothermal synthesis in Mg5(CO3)4(OH)24H2O and -Al2O3 mixtures are: the temperature of isothermal curing – 200 °C, duration – 1 h, and primary mixture Mg/Al molar ratio – 2. It was examined that the addition of NaOH and KOH in the primary mixtures, induces not only the interaction between raw materials, but also changes the sequence of obtained intermediate coumpounds during hydrothermal synthesis by reducing the hydrotalcite formation temperature and/or duration. It was determined that by changing the chemical composition of modificated hydrotalcites, the solid-state sintering conditions, microstructure parameters of mixed metal oxides and their nano sized compounds can be controlled. It was examined that chemisorption method is suitable for the immobilization of active components, i. e. transition metal ions, from their solutions into synthetic hydrotalcites. It was determined that hydrothermal synthesis is suitable for the formation of hydrotalcite layer on the Al/Al2O3 surfaces.

Los agentes anabolizantes prohibidos por la Comisión Médica del Comité Olímpico Internacional (COI) deben estar ausentes en las muestras de orina objeto de análisis. El límite de detección está condicionado por la sensibilidad del instrumento y la relación señal/ruido debida al material biológico coextraído junto con los analitos de interés. Las nuevas exigencias de sensibilidad del COI como la detección de nuevas sustancias utilizadas en dosis sensiblemente inferiores, obliga al replanteamiento de la estrategia analítica utilizada. El objetivo general de esta tesis es: desarrollar nuevas técnicas analíticas de alta sensibilidad para la detección de esteroides y otros anabolizantes en orina humana mediante: 1.- Estudio de la cromatografía liquida capilar para la cuantificación de las concentraciones de testosterona y epitestosterona en orina humana. 2.- Estudio de la purificación de la muestra previa al análisis instrumental. - Estudio del uso de la cormatografía de inmunoafinidad (IAC) en la purificación selectiva dela muestra. - Desarrollo de procedimientos mediante cromatografía líquida de alta resolución para la purificación de fracciones en los análisis de confirmación. 3.- Incremento de la sensibilidad en el análisis instrumental. - Estudio de la formación de tert-butildimetilsilil derivados como alternativa a los trimestilsilil derivados habitualmente utilizados. - Estudio de la utilización de nueva instrumentación basada en la espectrometría de masas de trampa de iones y en tándem (MS/MS) para alcanzar la sensibilidad y selectividad requerida por los nuevos estánderes impuestos por las organizaciones internacionales del área de la salud, en particular en el deporte.