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Développement d’un procédé de réduction des sulfites dans les vins / Development of a method to reduce sulfites in wineBakaï, Marie-France 11 December 2015 (has links)
Le SO2 est un additif utilisé en oenologie pour ses propriétés antiseptiques,antioxydantes et antioxydasiques. Il est introduit dans les vins en grandes quantités en raisonde son fort pouvoir de combinaison avec les dérivés carbonylés, ce qui limite son activité. Leproblème est que les teneurs maximales de SO2 autorisées ne permettent pas toujours uneprotection suffisante du vin contre les phénomènes de refermentation. L'objectif principal dece projet était de réduire la concentration en dioxyde de soufre dans les vins en éliminant unepartie des dérivés carbonylés responsables de la combinaison bisulfitique. La méthoderetenue a été l’extraction sur phase solide (SPE). Elle fait intervenir des interactions entre unephase liquide et un support solide poreux modifié avec une fonction extractive. Les travauxantérieurs ont permis de sélectionner l’hydrazine et la sulfonylhydrazine comme agentsd’extraction. Ces fonctions ont été fixées sur des supports polymères organiques selon deuxvoies : la fonctionnalisation de résines sulfoniques commerciales et la copolymérisation ensuspension de méthacrylate de glycidyle suivie d’une fonctionnalisation. Les supports solidesobtenus ont été caractérisés afin de valider la fonctionnalisation. Ils ont ensuite été testés surdes solutions modèles du vin et le procédé a prouvé son efficacité. La présence decontaminants dans les solutions a été recherchée avant d’appliquer la méthode sur du vin. / SO2 is an additive used in enology for its antiseptic, antioxidant and antioxydasic properties. It is introduced in wines in large quantities due to its high binding power with carbonyl compounds, which limits its activity. The maximum SO2 content authorized is notalways enough to avoid fermentative phenomena during wine storage. The main objective of this project was to develop a method to reduce the sulfur dioxide concentration in wines byeliminating some of carbonyl compounds responsible for the SO2 binding. The method used was solid-phase extraction (SPE). It involves interactions between a liquid and a porous solid support modified with an extractive function. Previous work allowed to select hydrazine andsulfonylhydrazine as extractive reagents. These functions were fixed on organic polymersupports according to two routes : functionnalization of commercial sulfonic resins and suspension copolymerization of glycidyl methacrylate (followed by the functionnalization). The solid supports obtained were characterized in order to validate the functionnalization.Then selective extractions were executed on model solutions. The diminution of carbonylcompounds concentration and SO2 content was showed by those experiments. The presence of contaminants in the solutions was investigated before applying the method to wine.
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Estudo de metodologias de controle de qualidade do Mo-99 utilizado no preparo de geradores de Mo-99/Tc-99m / Study of methodologies for quality control of 99Mo used in 99Mo/99mTc generatorsDaphne de Souza Said 17 March 2016 (has links)
O 99mTc é o radionuclídeo mais utilizado em medicina nuclear. No Brasil os geradores de 99Mo/99mTc são produzidos exclusivamente pelo Centro de Radiofarmácia do IPEN-CNEN/SP, com 99Mo importado de diferentes fornecedores. O 99Mo (t1/2 = 66 h), por ser um produto de fissão do 235U, pode conter impurezas radionuclídicas prejudiciais à saúde humana. Dessa forma, para que o gerador seja utilizado de forma segura, é necessário que o 99Mo seja avaliado por ensaios de controle de qualidade e atenda à alguma especificação descrita em farmacopeia. A Farmacopeia Europeia (FE) apresenta monografia, com parâmetros (identificação, pureza radioquímica e pureza radionuclídica), métodos de análise, e limites, para avaliação da qualidade da solução de [99Mo] na forma de molibdato de sódio, que é utilizada como matéria-prima no preparo dos geradores de 99Mo/99mTc. No entanto, observa-se uma dificuldade na implementação e execução dos métodos por parte dos produtores de geradores, com pouca literatura sobre o assunto, provavelmente devido à falta de praticidade dos métodos propostos e à extensa lista de reagentes utilizados. Nesse trabalho foram avaliados vários parâmetros de qualidade do 99Mo descritos na monografia da FE. Foram estudados métodos de separação do 99Mo de suas impurezas radionuclídicas por extração em fase sólida (SPE) e por TLC. Após separação por SPE, foi proposta a quantificação de metais por ICP-OES para avaliar a porcentagem de retenção de Mo e a porcentagem de recuperação de Ru e Te e Sr em diversos tipos de cartuchos, em substituição ao uso de radiotraçadores. Observou-se que a marca de cartucho de SPE para separação do 99Mo recomendada pela FE apresentou baixa recuperação para Ru, quando comparado aos outros cartuchos de troca aniônica disponíveis no mercado. Amostras de 99Mo de diferentes fornecedores mundiais foram analisadas. Observou-se que é possível realizar a quantificação de 103Ru em amostras de 99Mo mesmo com tempos de decaimento acima de 4 semanas. Um método alternativo de separação do 99Mo do 131I por TLC apresentou resultados promissores. Não foi feita a quantificação das impurezas radionuclídicas emissoras beta e alfa. Todas as amostras analisadas apresentaram resultados dentro das especificações da FE para pureza radioquímica (>95%) e pureza radionuclídica. / 99mTc is the most used radionuclide in nuclear medicine. In Brazil, the 99Mo/99mTc generators are exclusively produced by Radiopharmacy Center at IPENCNEN/ SP, by importing 99Mo from different suppliers. 99Mo (t1/2 = 66 h) is a fission product of 235U and it can have radionuclidic impurities that are prejudicial for human health. For safe use of generators, it is necessary to perform the evaluation of 99Mo by quality control tests in order to assess if 99Mo complies with the specifications. The European Pharmacopoeia (EP) presents a monograph for evaluation of the quality of the [99Mo] solution as sodium molybdate,that is used as raw material for 99Mo/99mTc generators production, including specification parameters (identification, radiochemical purity and radionuclidic purity), analysis methods and limits. However, it has been observed difficulties on the execution and implementation of these methods by the generators producers, with a few literature about this subject, probably due to complexity of the proposed methods. In this work, many quality control parameters of 99Mo described in the EP monograph were evaluated. Separation methods for 99Mo from its radionuclidic impurities by solid phase extraction (SPE) and TLC were studied. After SPE separation, the quantification of metals by ICP-OES to evaluate the percentage of retention of Mo and the percentage of recovery of Ru, Te and Sr using different types of cartridges were proposed, replacing radiotracers use. It was observed that the specific type of SPE cartridge recommended by the EP for separation of 99Mo presented low recoveries for Ru, compared to other available anion exchange SPE cartridges. 99Mo samples from different worldwide suppliers were analyzed. It was observed that quantification of 103Ru in 99Mo samples with decay time higher than 4 weeks is possible. An alternative method for separation of 131I from 99Mo showed promising results by TLC. The quantification of beta and alpha emitters radionuclidic impurities was not performed. All analysed samples presented results that comply with EP specifications for radiochemical purity (>95%) and for radionuclidic purity.
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Determinação de canabinóides em cabelo por microextração em fase sólida por Headspace e análise por espectrometria de massa associada à cromatografia em fase gasosa / Determination of cannabinoids in hair by Headspace solid-phase microextraction and gas chromatography-mass spectrometryCarolina Dizioli Rodrigues de Oliveira 21 July 2005 (has links)
Foi desenvolvido um método para determinar canabinóides (canabidiol, canabinol e delta-9-tetraidrocanabinol) no cabelo. Uma amostra de 10mg foi descontaminada com diclorometano, seguida de digestão alcalina, microextração em fase sólida por headspace (HS-SPME) e analisada por espectrometria de massa associada à cromatografia em fase gasosa (GC/MS). Os limites de detecção e de quantificação foram de 0,07 e 0,12 ng/mg, respectivamente, para todos canabinóides estudados. O método demonstrou ser simples, rápido, preciso e linear no intervalo de 0,12 a 12 ng/mg (r2 > 0,98). Amostras de cabelo de 8 usuários de Cannabis foram coletadas de pacientes provenientes de uma clínica dependentes pela equipe médica. O método mostrou-se eficiente em amostras de cabelos de usuários que faziam uso da droga pelo menos 10 vezes por semana. / A method was to develop to detect cannabinoids (cannabidiol, cannabinol and delta-9-tetrahydrocannabinol) in hair. A 10 mg of hair sample was descontaminated by dichloromethane followed by alkalin digestion, headspace solid-phase microextraction technique (HS-SPME) and analyzed by gas chromatography-mass spectrometry (CG/MS). The detection and quantitation limits were 0,07 and 0,12ng/mg respectively for all studied cannabinoids. The method proved to be simple, fast, precise and linear at the range of 0,12 to 12ng/mg (r2 > 0,98). Eight hair samples of Cannabis user were collected from patients at admittance from a dependence clinic by clinical staff. The method showed efficient in samples of users who use the drug at least 10 fold a week.
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Planejamento, S?ntese e Avalia??o de Derivados 1,2,4-Oxadiaz?licos com Potencial Atividade Tripanocida / Planning, Synthesis and Evaluation of potentially tripanocidal 1,2,4-Oxadiazolic DerivativesSantos, Paulo Pitasse 20 February 2017 (has links)
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Previous issue date: 2017-02-20 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Chagas disease was studied and described by the Brazilian sanitarist and physician Carlos Chagas in 1909. It is caused by the protozoan Trypanosoma cruzi and presents complex clinical manifestations. However, since its discovery, little progress has been made in the chemotherapeutic treatment of Chagas' disease. The only available drug for its treatment (benzonidazole) is not completely efficient and is associated with the development of several side effects. From the knowledge of the antiparasitic activity of the natural amidic alkaloid piperine, this work focused on the proposition of new structurally-similar molecules with trypanocidal potential. From the principles of bioisosterism, a series of new 1,2,4-oxadiazoles were proposed. Its synthesis was designed from the corresponding 3-arylacrylic acids to give the respective acyl chlorides by reaction with oxalyl chloride. The subsequent step involves O-acylation of the properly substituted benzamidoxime following the cyclization reaction of the oxadiazolic ring, which occurs in solid support (silica gel) using microwave irradiation. The characterization of the products was done by determination of melting points, 1H and 13C NMR, infrared espectrometry and high and low resolution mass spectrometry. The present work also presents information about the biological activity profile of the molecules synthesized against epimastigote forms of the T. cruzi protozoan and against primary mammalian cells, allowing the calculation of their selectivity indexes. Investigations about the possible mechanisms of action of the derivatives on T. cruzi indicate that there are no influences on the enzymatic action of the protease cruazain, on the cell cycle of the parasite or on the biosynthesis of membrane sterols catalyzed by the enzyme CYP51. The developed sinthetic methodology can be applied in the expansion of the series of analogues derivatives. The perspectives of this work also include the biological evaluation against amastigote and trypomastigote forms of the parasite. / A doen?a de Chagas foi estudada e descrita pelo m?dico sanitarista e cientista brasileiro Carlos Chagas, em 1909. ? causada pelo protozo?rio Trypanossoma cruzi, apresentando manifesta??es cl?nicas complexas. No entanto, desde sua descoberta, pouco se avan?ou no tratamento quimioter?pico da doen?a de Chagas, sendo o f?rmaco dispon?vel (benzonidazol) pouco eficiente e associado ? manifesta??o de diversos efeitos colaterais. A partir do conhecimento da atividade antiparasit?ria da amida natural piperina, este trabalho focou-se na proposi??o de novas mol?culas estruturalmente semelhantes com potencial tripanocida. A partir dos princ?pios do bioisosterismo, foi proposta uma s?rie de novos 1,2,4-oxadiaz?is diferentemente substitu?dos. Sua s?ntese foi concebida partir dos ?cidos 3-arilacr?licos correspondentes, obtendo-se os respectivos cloretos de acila, atrav?s da rea??o com cloreto de oxalila. A etapa posterior envolve a O-acila??o da benzamidoxima adequadamente substitu?da, seguida do fechamento do anel oxadiaz?lico, que se d? em em suporte s?lido (s?lica-gel) empregando-se irradia??o de micro-ondas. A caracteriza??o dos produtos foi feita atrav?s de ponto de fus?o, RMN 1H e 13C, espectrometria no infravermelho e espectrometria de massas de alta e baixa resolu??o. O presente trabalho ainda traz informa??es quanto ao perfil de atividade biol?gica das mol?culas sintetizadas frente a formas epimastigotas do protozo?rio Trypanosoma cruzi e frente a c?lulas prim?rias de mam?feros, permitindo que se calculasse o seu ?ndice de seletividade. Investiga??es quanto a poss?veis mecanismos de a??o dos derivados sobre o T. cruzi indicam n?o haver influ?ncias sobre a a??o enzim?tica da protease cruza?na, sobre o ciclo celular do parasito, nem sobre a bioss?ntese de ester?is de membrana, catalisada pela enzima CYP51. A metodologia qu?mica desenvolvida poder? ser aplicada na s?ntese de outros an?logos. As perspectivas deste trabalho incluem ainda a avalia??o biol?gica frente a formas amastigota e tripomastigota do parasito
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\"Análise de fármacos em fluidos biológicos empregando o acoplamento SPME-LC/MS\" / \"Analysis of pharmaceutical compounds in biological fluids using on-line SPME-LC/MS\"Alves, Claudete 19 April 2006 (has links)
Os métodos convencionais para a determinação de fármacos em fluidos biológicos baseiam-se em técnicas cromatográficas e imunoquímicas. O tratamento prévio de amostras biológicas, o qual abrange as etapas de extração, pré-concentração e clean-up", tem sido requerido nas análises de fármacos, para aumentar a sensibilidade e seletividade analítica. No entanto, nos últimos anos, com o avanço das técnicas instrumentais, diversas técnicas têm sido avaliados para a análise de diferentes fármacos em fluidos biológicos, destacando-se entre elas a Microextração em Fase Sólida (SPME) e a Cromatografia Líquida acoplada a Espectrometria de Massas (LC/MS). A SPME apresenta uma série de vantagens em relação às técnicas de extração tradicionais, ou seja: não requer instrumentação analítica sofisticada, não utiliza solvente orgânico, permite automação das análises, a reutilização das fibras extratoras e integra em um único sistema, a extração, concentração e introdução da amostra no sistema cromatográfico. Neste trabalho, foi desenvolvida uma interface versátil e de baixo custo, que permite o acoplamento das técnicas SPME-LC/MS para análise dos fármacos antidepressivos tricíclicos e anticonvulsivantes. O planejamento fatorial empregado mostrou ser uma ferramenta estatística importante e simples, sendo obtido mais informações com um número menor de experimentos, avaliando não só os efeitos principais como os efeitos de interação de todas as variáveis nas respostas. As condições cromatográficas otimizadas foram adequadas para a análise por LC/MS. Os níveis de detecção alcançados ressaltam a importância e destaque da técnica de cromatografia líquida de alta eficiência acoplada à espectrometria de massas (LC/MS). O método desenvolvido, tanto para os fármacos antidepressivos tricíclicos como para os anticonvulsivantes, mostrou especificidade, precisão, linearidade e limite de quantificação adequado para a análise. / Conventional methods used for the determination of drugs in biological fluids are based on chromatographic and immunochemical techniques. The biological samples treatment - which includes extraction, pre-concentration and clean up steps has been required in drugs analysis in order to increase both analytical sensitivity and selectivity. Nevertheless, lately, within the advancements in instrumentation, different techniques have been evaluated for the analysis of different drugs in biological fluids, such as: solid phase microextraction (SPME) and liquid chromatography coupled to mass spectrometry (LC/MS). SPME presents many advantages towards the conventional extraction techniques (soxhlet, LLE and SPE), which include: use of simple analytical instrumentation, analysis automation, reuse of extractor fibers and integration of extraction, concentration and sample introduction in the same chromatographic system. In this work, a versatile and low cost interface was developed, which allows the coupling of SPME-LC/MS techniques to tricyclic antidepressants and anticonvulsivant drugs analysis. The employed factorial design has shown to be a simple and useful statistical tool. With this device more information could be obtained with fewer experiments by evaluating not only the main interaction effects but also the interaction effects of all variables on the results. The optimized chromatographic conditions were adequate for LC/MS analysis. The obtained detection levels highlight the importance of high performance liquid chromatography coupled to mass spectrometry (LC/MS). The developed method, for both tricyclic antidepressants and anticonvulsivants drugs, has presented specificity, accuracy, linearity and adequate limit of detection for this analysis.
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Electrochemical Remedy and Analysis for the Environment Based on the New Polymer-DNA Composite Material.Hussain, Noor Feuza 16 August 2005 (has links)
In this work a new material, the conducting polymer-DNA composite, has been reported for the first time due to its promise in micro extraction, transfer, and release of cations under controlled potential conditions by using electrochemically assisted solid phase micro extraction (SPME). The Polypyrrole/DNA composite can be formed easily by oxidation of pyrrole monomers in the presence of chromosomal DNA by electropolymerization. Environmental significant pollutants such as Cd, Pb, Hg, Co, Zn, Cu, and Bi metal ions can be extracted from the aqueous solution and are able to be transferred to another medium defined as the release solution where the metals were detected by anodic stripping voltammetry. Using Cd2+ as a model, this method has been examined to optimize its operational condition. Extraction efficiency and potential interference for this method were studied.
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Solid-phase glycoconjugate synthesis : on-resin analysis with gel-phase ¹9F NMR spectroscopyMogemark, Mickael January 2005 (has links)
<p>An efficient and versatile non-destructive method to analyze the progress of solid-phase glycoconjugate synthesis with gel-phase <sup>19</sup>F NMR spectroscopy is described. The method relies on use of fluorinated linkers and building blocks carrying fluorinated protective groups. Commercially available fluorinated reagents have been utilized to attach the protective groups. </p><p>The influence of resin structures for seven commercial resins upon resolution of gel-phase <sup>19</sup>F NMR spectra was investigated. Two different linkers for oligosaccharide synthesis were also developed and successfully employed in preparation of α-Gal trisaccharides and a n-pentenyl glycoside. Finally, reaction conditions for solid-phase peptide glycosylations were established.</p>
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The MHC-glycopeptide-T cell interaction in collagen induced arthritis : a study using glycopeptides, isosteres and statistical molecular design in a mouse model for rheumatoid arthritisHolm, Lotta January 2006 (has links)
<p>Rheumatoid arthritis (RA) is an autoimmune disease affecting approximately 1% of the population in the western world. It is characterised by a tissue specific attack of cartilage in peripheral joints. Collagen induced arthritis (CIA) is one of the most commonly used animal models for (RA), with similar symptoms and histopathology. CIA is induced by immunisation of mice with type II collagen (CII), and the immunodominant part was previously found to be located between residues 256-270. This thesis describes the interaction between the MHC molecule, glycopeptide antigens from CII and the T cells that is essential in development of CIA. The glycopeptide properties for binding to the mouse MHC molecule Aq have been studied, as well as interaction points in the glycopeptide that are critical for stimulation of a T-cell response.</p><p>The thesis is based on five studies. In the first paper the minimal glycopeptide core, that is required for binding to the Aq molecule while still giving a full T cell response was determined. The second paper studied the roles of amino acid side-chains and a backbone amide bond as T-cell contact points. In the third paper the hydrogen bond donor-acceptor characteristics of the 4-OH galactose hydroxyl group of the glycopeptide was studied in detail. In the fourth paper we established a structure activity relationship (QSAR model) for (glyco)peptide binding to the Aq molecule. Finally, the stereochemical requirements for glycopeptide binding to the Aq molecule and for T-cell recognition was studied in the fifth paper.</p><p>The study was performed using collagen glycopeptide analogues, which were synthesised on solid phase. Amide bond and hydroxyl group isosteres were introduced for study of hydrogen bond donor-acceptor characteristics. Statistical methods were used to design a representative peptide test set and in establishing a QSAR model.</p><p>The results give a deeper understanding of the interactions involved in the ternary MHC-glycopeptide-T cell complex. This information contributes to research directed towards finding new treatments for RA.</p>
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Development of Field-adapted Analytical Methods for the Determination of New Antimalarial Drugs in Biological FluidsLindegårdh, Niklas January 2003 (has links)
<p>This thesis deals with the development of analytical methods for the determination of new antimalarial drugs in biological fluids. The goal was to develop methods that facilitate clinical studies performed in the field, such as capillary blood sampling onto sampling paper.</p><p>Methods for the determination of atovaquone (ATQ) in plasma, whole blood and capillary blood applied onto sampling paper were developed and validated. </p><p>Automated solid-phase extraction (SPE) and liquid chromatography (LC) with UV absorbance detection was used to quantify ATQ. Venous blood contained higher levels of ATQ than capillary blood after a single dose of Malarone (ATQ + proguanil).</p><p>Ion-pairing LC was used to separate amodiaquine (AQ), chloroquine (CQ) and their metabolites on a CN-column. A method for quantification of AQ, CQ and their metabolites in capillary blood applied onto sampling paper was developed and validated. Perchloric acid and acetonitrile were used to facilitate the extraction of the analytes from the sampling paper. The liquid extract was further cleaned by SPE.</p><p>Methods for the determination of piperaquine (PQ) in plasma and whole blood using SPE and LC were developed and validated. Addition of trichloroacetic acid (TCA) to the samples prior to injection into the LC-system significantly enhanced the efficiency for the PQ peak. Serum and whole blood contained higher levels (about 300 nM) of PQ than plasma (about 200 nM) after a single oral dose of 340 mg PQ. This indicates that PQ may be taken up in the leucocytes and thrombocytes.</p>
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Synthesis and biological evaluation of Bicyclic β-Lactams and 2-Pyridinones : Pilicides Targeting Pilus Biogenesis in Pathogenic BacteriaEmtenäs, Hans January 2003 (has links)
New methods have been developed for the synthesis of bicyclic β-lactams and 2-pyridinones by combining acyl Meldrum’s acids and Δ2-thiazolines. The 2-pyridinones were synthesised both in solution using conventional heating or microwave assisted heating as well as by solid supported chemistry. The compounds (pilicides) were designed to interfere with the assembly of pili in uropathogenic E. coli by inhibiting the periplasmic chaperones. The affinity of the pilicides to the chaperones was investigated with surface plasmon resonance technique (Biacore) and with relaxation-edited 1H NMR spectroscopy experiments. Finally, the pilicides were investigated for their ability to inhibit pili formation in uropathogenic E. coli in a hemagglutination assay, where members of the 2-pyridinone family proved to be able to cause depiliation.
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