Orientadores: Regina Buffon, Regina Mara Silva Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-05T04:42:43Z (GMT). No. of bitstreams: 1 Paula_VanderleiInaciode_M.pdf: 3879101 bytes, checksum: f5ec10f585405c9d2de0c5df2a99eb1b (MD5) Previous issue date: 2004 / Mestrado / Quimica Inorganica / Mestre em Química

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In the last several decades, polycyclic aromatic hydrocarbons (PAHs) have been the subject of extensive investigation due to their presumed abundance in the interstellar medium (ISM). My thesis concentrated on investigating the dissociation of ionized PAH molecules in the gas phase under similar conditions of the ISM. The twelve PAHs studied were naphthalene (NAP), anthracene (ANT), phenanthrene (PHN), cyclopenta[d,e,f] phenanthrene (CYC), pyrene (PYR), fluoranthene (FLN), perylene (PER) and coronene (COR). In addition, two dihydro PAHs were studied to examine potential intermediates in H2 catalysis, 1,2-dihydronaphthalene (DHN) and 9,10-dihydrophenanthrene (DHP), and two stabilized fragments of PAHs, acenaphthylene (ACE), fluorene-H (FLU). These ions were studied using atmospheric pressure chemical ionization (APCI) to generate the ions and the fragmentation was produced by collision-induced dissociation (CID). The CID experiments were done at different lab frame collision energies to produce breakdown curves for all fragments in each molecule. These curves were fitted by using Rice – Ramsperger-Kassel- Marcus (RRKM) theory to derive the activation energy (E0) at 0K and the entropy of activation (∆‡ S) for each reaction. The primary dissociation channel observed was H loss and this fragmentation channel was a common fragment to all PAHs molecules studied. Also, there were other fragments (CH3, C2H2, C4H2) observed in all of these molecules studied except perylene and coronene. The final step in this project was to compare these results with results derived from imaging photoelectron photoion coincidence spectroscopy (iPEPICO) reported by West and co-workers in order to determine the suitability of the APCI-CID technique for deriving reliable kinetic parameters for this class of ions.

L’étude du lien entre l’exposition de l’Homme aux substances chimiques, notamment via son alimentation,et sa santé est un sujet de préoccupation majeure dans notre société qui présente des challenges multiples.Nous nous sommes attelés à l’un d’entre eux par la production de données analytiques fiables relatives à la contamination des denrées alimentaires et des fluides biologiques humains. Le développement de méthodes analytiques reposant sur des technologies en rupture, à même de s’adresser aux paris de la mesure de composés chimiques émergents (e.g. les retardateurs de flamme bromés) ou historiques mais sous le prisme de la sensibilité et du haut débit (e.g. les stéroïdes, les pesticides organochlorés, les dioxines et les polychlorobiphényles) a été au cœur de ce travail. Le couplage GC/APCI/MS sur système triple quadripolaire s’est imposé au cours de nos évaluations. L’association de la chromatographie en phase gazeuse et de l’ionisation chimique à pression atmosphérique a apporté un gain en sélectivité remarquable comparée aux approches traditionnellement retenues dans le domaine et a autorisé l’exploration des ultra-traces dans des matrices biologiques complexes. Cette géométrie nous a permis d’innover en pratiquant des séparations rapides sur colonne capillaire ultra-courte de 2,5 m. La vitesse de balayage et l’excellente sensibilité de l’analyseur de masse nous ont en outre donné accès à une analyse quantitative fiable et multi-paramètres. Ce travail ouvre d’excellentes perspectives vis-à-vis de la production de données d’exposition externe et interne élargies en réponse aux défis à venir entourant la caractérisation de l’exposome Humain. / The study of the link between Human exposure tochemical substances (notably via his food the intake) and Health, is a major concern in our society and poses many challenges. We endeavoured to address one of them by producing reliable analytical data on foodstuffs and human biological fluids contamination. The development of analytical methods based on breakthrough technologies, capable of challenging theemerging (e.g. brominated flame retardants) or historical compounds measurement but through the prism of sensitivity and high throughput (e.g. steroids,organochlorine pesticides, dioxins andpolychlorobiphenyls), was at the heart of our work.Using a GC/APCI/MS with a triple quadripole systememerged as a favorable choice as our evaluations progressed. The association of gas chromatography and atmospheric pressure chemical ionisation brought in a remarkable gain in terms of selectivity, compared to the approaches traditionally selected in this field, andauthorized ultra-trace exploration in complex biologicalmatrices. This geometry allowed us to innovate by performing fast separations on an ultra-short 2.5 mcolumn. Besides, the mass analyser scan speed and high sensitivity gave us access to a reliable and multiparameters quantitative analysis. This work opens up excellent perspectives for the production of expanded external and internal exposure data to meet the future challenges surrounding Human exposome characterisation.

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Submitted by Elizabete Silva (elizabete.silva@ufes.br) on 2015-04-08T20:23:10Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Lilian Valadares Tose.pdf: 22786688 bytes, checksum: 4b658f7b5444bc01ea9bd4002e47455e (MD5) / Approved for entry into archive by Elizabete Silva (elizabete.silva@ufes.br) on 2015-04-14T19:21:33Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Lilian Valadares Tose.pdf: 22786688 bytes, checksum: 4b658f7b5444bc01ea9bd4002e47455e (MD5) / Made available in DSpace on 2015-04-14T19:21:33Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Lilian Valadares Tose.pdf: 22786688 bytes, checksum: 4b658f7b5444bc01ea9bd4002e47455e (MD5) Previous issue date: 2014-12 / A análise de hidrocarbonetos por técnicas de ionização a pressão atmosférica ou ambiente continua a ser um desafio na espectrometria de massas. Normalmente, a ionização ocorre através de mecanismos de protonação e desprotonação. Para isso, as moléculas de interesse devem apresentar um grupo básico ou ácido que proporcionem a geração de íons [M+H]+ ou [M-H]-. Para superar essa limitação, um método analítico simples, fácil, rápido e poderoso foi desenvolvido com sucesso, adaptado a partir da literatura, para ionizar saturado e insaturado, linear, ramificado, e hidrocarbonetos cíclicos, bem como hidrocarbonetos poliaromáticos e heteroaromáticos presentes em frações de hidrocarbonetos e de misturas de parafina/petróleo bruto utilizando ionização química à pressão atmosférica (APCI), favorecido pela utilização de solventes alifáticos de cadeia curta em um espectrômetro de massas FT-ICR. Entre os reagentes alifáticos estudados, isoctano proporcionou os melhores resultados quando comparado com outros solventes. Além disso, foram estudados outros interferentes do processo de ionização, como concentração da solução injetada e misturas parafina/óleo, que influenciavam desde o perfil dos espectros até as principais classes de compostos identificados. O método torna possível a ionização de hidrocarbonetos pela produção de íons [M -H]+ sem ocorrência de fragmentação. / The analysis of hydrocarbon using atmospheric or ambient ionization techniques still remains a challenge in mass spectrometry. Traditionally, the ionization occurs via protonation or deprotonation. The molecules of interest must have a basic or acidic group to generated [M + H]+ or [M - H]- ions. To overcome such limitation, it is proposed a simple, easy, fast and powerful analytical methodology to ionize saturated (linear and branched), unsaturated, and cyclic hydrocarbons as well as polyaromatic and heteroaromatic hydrocarbonsby atmospheric pressure chemical ionization (APCI) using small hydrocarbons as reagents in a FT-ICR mass spectrometer. These molecules may be present in hydrocarbon fraction samples and paraffin/crude oil blends. Among the APCI hydrocarbon reagents studied, isooctane provided the best results when compared to pentane, hexane, cyclohexane and heptane. The method renders the ionization of hydrocarbons to yield [M – H]+ ions with no associated fragmentation using nitrogen as sheath gas.

Submitted by Elizabete Silva (elizabete.silva@ufes.br) on 2015-04-08T20:23:10Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Lilian Valadares Tose.pdf: 22786688 bytes, checksum: 4b658f7b5444bc01ea9bd4002e47455e (MD5) / Approved for entry into archive by Elizabete Silva (elizabete.silva@ufes.br) on 2015-04-14T19:21:33Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Lilian Valadares Tose.pdf: 22786688 bytes, checksum: 4b658f7b5444bc01ea9bd4002e47455e (MD5) / Made available in DSpace on 2015-04-14T19:21:33Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Lilian Valadares Tose.pdf: 22786688 bytes, checksum: 4b658f7b5444bc01ea9bd4002e47455e (MD5) Previous issue date: 2014-12 / A análise de hidrocarbonetos por técnicas de ionização a pressão atmosférica ou ambiente continua a ser um desafio na espectrometria de massas. Normalmente, a ionização ocorre através de mecanismos de protonação e desprotonação. Para isso, as moléculas de interesse devem apresentar um grupo básico ou ácido que proporcionem a geração de íons [M+H]+ ou [M-H]-. Para superar essa limitação, um método analítico simples, fácil, rápido e poderoso foi desenvolvido com sucesso, adaptado a partir da literatura, para ionizar saturado e insaturado, linear, ramificado, e hidrocarbonetos cíclicos, bem como hidrocarbonetos poliaromáticos e heteroaromáticos presentes em frações de hidrocarbonetos e de misturas de parafina/petróleo bruto utilizando ionização química à pressão atmosférica (APCI), favorecido pela utilização de solventes alifáticos de cadeia curta em um espectrômetro de massas FT-ICR. Entre os reagentes alifáticos estudados, isoctano proporcionou os melhores resultados quando comparado com outros solventes. Além disso, foram estudados outros interferentes do processo de ionização, como concentração da solução injetada e misturas parafina/óleo, que influenciavam desde o perfil dos espectros até as principais classes de compostos identificados. O método torna possível a ionização de hidrocarbonetos pela produção de íons [M -H]+ sem ocorrência de fragmentação. / The analysis of hydrocarbon using atmospheric or ambient ionization techniques still remains a challenge in mass spectrometry. Traditionally, the ionization occurs via protonation or deprotonation. The molecules of interest must have a basic or acidic group to generated [M + H]+ or [M - H]- ions. To overcome such limitation, it is proposed a simple, easy, fast and powerful analytical methodology to ionize saturated (linear and branched), unsaturated, and cyclic hydrocarbons as well as polyaromatic and heteroaromatic hydrocarbonsby atmospheric pressure chemical ionization (APCI) using small hydrocarbons as reagents in a FT-ICR mass spectrometer. These molecules may be present in hydrocarbon fraction samples and paraffin/crude oil blends. Among the APCI hydrocarbon reagents studied, isooctane provided the best results when compared to pentane, hexane, cyclohexane and heptane. The method renders the ionization of hydrocarbons to yield [M – H]+ ions with no associated fragmentation using nitrogen as sheath gas.

Depuis plusieurs années, la recherche dans le domaine des bioénergies s'oriente de plus en plus vers l'utilisation des microorganismes (bactéries, levures, moisissures et microalgues) pour la production de biocarburants. Face au contexte actuel de développement durable, l'utilisation des microorganismes oléagineux photoautotrophes (cyanobactéries et microalgues) semble potentiellement plus intéressante d'un point de vue économique (énergie solaire) et environnemental (assimilation de CO2) malgré des productions plus faibles que celles des microorganismes oléagineux hétérotrophes (levures et moisissures). L'objectif général de ces travaux de thèse a donc été d'étudier l'accumulation de lipides neutres et d'hydrocarbures chez Botryococcus braunii race A (chlorophycée unicellulaire d'eau douce), sélectionnée pour son potentiel de production après une étude bibliographique et d'évaluer les mécanismes naturels d'exsudation de ces métabolites. Afin de fiabiliser la quantification et l'identification des composés lipidiques produits par la microalgue, des méthodes d'analyse qualitative et quantitative par HPLC ont été mises au point. Les résultats analytiques ont permis de montrer que les méthodes d'extraction et quantification décrites dans la littérature conduisaient à surévaluer la teneur en hydrocarbures synthétisés par la souche B. braunii Utex 572. Les études menées lors de ce travail de thèse ont également permis de déterminer l'impact des principaux facteurs abiotiques (milieu de culture, pH, CO2, intensité lumineuse, salinité) sur la production de biomasse, lipides neutres et hydrocarbures par B. braunii et d'en définir les conditions optimales. L'étude de la flore bactérienne naturellement présente dans les cultures de B. braunii en conditions non axéniques et de sa dynamique a montré que celle-ci n'avait pas ou peu d'impact sur la production de biomasse et de lipides neutres chez B. braunii dans les conditions de l'étude. L'application d'un stress oxydatif à une culture de B. braunii en phase stationnaire n'a pas engendré le phénomène de « milking » recherché mais a eu un impact positif sur l'accumulation de lipides intracellulaires et sur la synthèse de triglycérides. / Biofuels produced from vegetable oils or microbial cultures, are an alternative to fossil fuels that can reduce the human impact on the environment. For several years, research in the field of bioenergy is moving increasingly toward the use of microorganisms (bacteria, yeasts, fungi and microalgae) for the production of biofuels. In the current context of sustainable development, the use of photoautotrophic oleaginous microorganisms (cyanobacteria and microalgae) seems potentially more interesting economically (solar energy) and environmentally (CO2 assimilation) despite lower production rates than those of heterotrophic oleaginous microorganisms (yeasts and moulds). The overall objective of this thesis has been to study the accumulation of neutral lipids and hydrocarbons in the A-race Botryococcus braunii (unicellular green alga of freshwater), selected on its potential production after literature review, and to evaluate the mechanisms of natural exudation of these metabolites. To reliable quantification and identification of lipid compounds produced by microalgae, methods of qualitative and quantitative analysis by HPLC were developed. The analytical results have shown that the extraction and quantification methods described in the literature led to overestimate the amount of hydrocarbons synthesized by the strain B. braunii Utex 572. The studies in this thesis have also identified the impact of key abiotic factors (culture medium pH, CO2, light intensity, salinity) on biomass production, neutral lipids and hydrocarbons by B. braunii and to define the optimal conditions of production. The study of the bacterial flora naturally present in cultures of B. braunii under non axenic conditions and its dynamics showed that it had little or no impact on the production of biomass and neutral lipids in B. braunii in the conditions of the study. The application of oxidative stress to a culture of B. braunii at the stationary phase did not cause the sought phenomenon of "milking" but had a positive impact on the accumulation of intracellular lipid and triglyceride synthesis.

Qualitative and quantitative analysis of trace substances determined by Mass spectrometry has unique advantages which can¡¦t be replaced. For example, the detection limit of common gas sensors are difficult to lower than 1 ppm, and the sensitivity, selectivity, period of use and stability are not ideal. The detection limit of mass spectrometer is general low to 0.01 ppm. Furthermore, all substances in the sample can be simultaneous analysis by mass spectrometer, but single gas sensor measurements cannot. In this study, dielectric barrier discharge plasma is used in environmental mass spectrometry analysis. This study develops an innovative balanced T-shaped dielectric barrier discharge (DBD) plasma generator for generating atmospheric plasma to replace the linear type plasma generator. Through the change of the geometric configuration and the drive phase develop T-shaped dielectric barrier discharge plasma, the balanced design can fully cancel the high potential and noise. The main objective of this study for the more traditional linear electrodes of the study's original novel T-shaped electrodes of different, including mass spectrometry, spectroscopy, and some basic electrical measurements, and by changing the electrode design, voltage, temperature, gas flow, gas flow rate, diameter and other parameters of the dielectric, and compare their differences and to explore the most suitable parameters. The results showed that T-shaped design of the research and development of innovation through the elimination of the exit pressure put EFI flame can indeed significantly reduce sample oxidation and generate fragments of the situation, and thus improve the mass spectrum of readability and debris interference, thus improving the detection limit , especially for some with a benzene ring and long-chain carbon samples. The experimental results confirm that the development of the Institute of Atmospheric Pressure Plasma free system can be prolonged to produce high concentrations of plasma gas as a free source of the mass spectrometry system, and provides more than 107 cm-3 ion concentration. MS-free analysis of the system can be directly on the gas, liquid and solid samples, the test do not need complicated traditional mass spectrometry analysis of the required sample pre-treatment steps, you can get a clear identification of high mass spectrometry signal. In addition to introducing the basic principles and structure of the atmospheric pressure plasma discharge device, and take advantage of many samples test for the different plasma mass spectrometry free system performance verification.

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