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.

Mykotoxine sind giftige Naturstoffe, die im Rahmen des Sekundärstoffwechsels von Schimmelpilzen beim Wachstum auf pflanzlichen Substraten gebildet werden. Zu den bekanntesten Mykotoxinen zählt das Ochratoxin A (OTA), welches überwiegend in Getreide und davon abgeleiteten Erzeugnissen, aber auch in Wein und Kaffee sowie Gewürzen und Bier nachgewiesen wurde. OTA ist unter anderem immunotoxisch, nephrotoxisch und besitzt teratogene sowie kanzerogene Eigenschaften. Darüber hinaus wird OTA eine hormonelle Wirkung zugesprochen. Aufgrund der Toxizität und des relativ häufigen Vorkommens in Lebensmitteln wurden für OTA Grenzwerte festgelegt. Diese liegen für Wein, Röstkaffee und diätetische Produkte zwischen 0,5 mikrogramm /kg und 10 mikrogramm /kg. Grenzwerte für Gewürze und Bier sind geplant. Im Rahmen der Methodenentwicklung zur Bestimmung von OTA in Lebensmitteln wurden verschiedene clean-up-Techniken miteinander verglichen. Dabei wurde vor allem den kombinierten Ionentauscher/reversed phase-Säulen und der LC-MS/MS wesentliche Bedeutung beigemessen. Innerhalb der Methodenvalidierung wurden die Ergebnisse mit dem entsprechenden Standardverfahren verglichen. Es konnte gezeigt werden, dass mit oben genanntem Material in Kombination mit der LC-MS/MS sehr gute Ergebnisse erzielt werden können. Diese wurden im Rahmen der Validierung durch statistische Auswertung bestätigt. Ferner wurden im Rahmen der Methodenentwicklung, speziell bei der Bestimmung von OTA in Kaffee, Extraktionstechniken miteinander verglichen. Dabei wurde die bislang kaum beachtete ASE (Accelerated Solvent Extraction, Dionex) sowie Ultraschallextraktion mit der Schüttelextraktion aus der gültigen Norm verglichen und ihre Anwendbarkeit auf weitere Lebensmittel geprüft. In diesem Zusammenhang waren die ASE und Ultraschallextraktion der konventionellen Schüttelextraktion überlegen. Darüber hinaus wurde die Ultraschallextraktion in Kombination mit dem Ionentauscher/reversed phase clean-up erfolgreich auf Weizen und Chili angewandt. Parallel zur Methodenentwicklung wurde die Stabilität und Homogenität von OTA in Wein und Röstkaffee untersucht. Sowohl die Homogenität als auch die Stabilität des Analyten sind wichtige Faktoren bei der Entwicklung neuer Verfahren, da zusammen mit Ergebnissen der Validierung, die Messunsicherheit innerhalb neuer Verfahren eingegrenzt werden. / Mycotoxins are naturally occurring toxic substances and produced as secondary metabolites by fungi which are growing on plants predominantly. One of the most interesting mycotoxins is ochratoxin A (OTA), which was found in several foods and feed stuff like wheat and its related products, wine, coffee, spices and beer. Among other things OTA is immunotoxic, nephrotoxic and has teratogenic and cancerogenic properties. Further more OTA shows hormonal effects. Because of its toxicity and common appearance in food and feed the OTA content had to be regulated in European and or national directives. The maximum values are determined between 0.5 micrograms/kg and 10 micrograms/kg for wine, roasted coffee and dietetic products. Other maximum levels for beer and spices are intended. During the investigation of analytical methods for the determination of OTA in food stuff different clean-up techniques were compared. Thereby the mixed anion exchange/reversed phase clean-up in combination with LC-MS/MS was researched intensively. Within method validation the results were compared with the corresponding standard methods. This work shows that the mixed mode clean-up in combination with LC-MS/MS gives excellent results. These results were statistically confirmed during method validation. Further more different extraction techniques were compared during the development of analytical methods, especially for the determination of OTA in coffee. Thereby the ASE (accelerated solvent extraction, Dionex) and the ultrasonic extraction were compared with the shaking technique from current standard methods. The adaptability for other food and feed products was researched as well. In this context the new extraction techniques were superior to conventional shaking techniques. In addition the ultrasonic extraction with mixed mode clean-up and LC-MS/MS detection was applied to chilli and wheat effectively. Besides the investigation of analytical methods the stability and homogeneity of OTA in wine and roasted coffee was researched. The homogeneity and stability of OTA in matrix are very important factors during the investigation of analytical methods. In combination with the relevant results of the method validation these results can be used to determine the uncertainty of the new analytical methods.

A contaminação de aguas pela mistura Benzeno, Tolueno, Etilbenzeno e Xilenos (BTEX) vem gerando a necessidade do desenvolvimento de metodologias altamente eficientes na remoção de poluentes e de metodologias analíticas para monitoramento ambiental suficientemente sensíveis, seletivos, reprodutíveis e rápidos. Nesse contexto, adsorventes com propriedades magnéticas aparecem como alternativas eficientes, de baixo custo e de fácil automação, inclusive possibilitando o desenvolvimento de metodologia analítica baseada na extração em fase sólida magnética (m-SPE), que vem ganhando interesse crescente por permitir extração rápida e análise efetiva dos poluentes com alta sensibilidade. A busca por adsorventes adequados exige o estudo de materiais com grande área superficial, funcionalizáveis e estáveis como as sílicas, mais especificamente uma comparação entre os tipos de sílica e do tipo de agente funcionalizante nas propriedades de adsorção/dessorção. Sílicas mesoporosas oraganofuncionalizas magnéticas com diferentes morfologias foram preparadas: sílica mesoporosa ordenada MCM-48 e MCM-41, bem como nanoparticulas esféricas de sílica mesoporosa (NPSiO2). A formação da silica mesoporosa ordenada começa com a preparação de um template de CTAB sobre o qual são depositados/formados os materiais MCM-41 e MCM-48. A concentração de CTAB deve ser controlada com cuidado pois estruturas com diferentes morfologias podem ser geradas variando-se esse parâmetro. As análises de espectroscopia FTIR, DRX e sorção de N2 revelaram que os materiais preparados são sílicas mesoporosas ordenadas com arranjo tipo giroide 3D (MCM-48) ou do tipo hexagonal (MCM-41) com área superficial respectivamente de 1212 m2.g-1 e 1159 m2.g-1. Além disso, as imagens de MET do material MCM-48 mostraram tamanho médio de partícula igual a 116 nm ± 15 nm. Para facilitar a remoção do adsorvente, nanopartículas de magnetita (SPION) foram incorporadas na superfície dos materiais adsorventes. O tempo de remoção típico foi determinado como sendo de 1 minuto. A organofuncionalização da sílica com octadecilssilano (C18), octilssilano (C8) e difenilssilano (Ph2) foi confirmada por espectroscopia FTIR e análise termogravimétrica demostrando a presença e a percentagem em massa dos grupos orgânicos em cada tipo de sílica mesoporosa. Usando como referência sílica gel 60 comercial (Sílica), foram comparadas as propriedades de adsorção frente a BTEX em agua, quando o agente funcionalizante é C8, C18 ou Ph2. Os resultados indicaram que as capacidades de adsorção, segundo o modelo de Langmuir, seguem a seguinte ordem C8≥C18>>Ph2. A partir disso, as propriedades de adsorção das demais sílicas funcionalizadas com C8 foram comparadas determinando-se que as capacidades de adsorção, segundo o modelo de Langmuir, estão na seguinte ordem: MCM-48>Sílica>NPSiO2>MCM-41. O nanocompósito organofuncionalizado MCM48-C8/SPION, que mostrou as melhores propriedades de adsorção, foi usado para a extração em fase sólida magnética (m-SPE) de BTEX em agua de posto de gasolina. Verificou-se que apenas 30 mg de adsorvente, 5 min de contato com a solução de BTEX, 1 min para remoção do adsorvente e 1 min para a extração foram suficientes para concentração/recuperação de BTEX de agua pela técnica de m-SPE, viabilizando a análise quantitativa, no caso por CG-MS. / The contamination of water bodies by Benzene, Toluene, Ethylbenzene and Xylenes (BTEX) has prompted the development of more efficient methodologies for their removal and the development of sufficiently sensitive, selective, reproducible and fast analytical methods for environmental monitoring. In this context, adsorbent materials with magnetic properties appear as efficient, low cost and easy automation alternatives, including the development of analytical methods based on magnetic solid phase extraction (m-SPE), which has gaining increasing interest since allows rapid extraction and effective analysis of pollutants with high sensitivity. The search for suitable adsorbents requires the study of materials with large surface area, functionalizable and stable as the silica\'s family, more specifically a comparison between the types of silica and the type of functionalizing agent on their adsorption/desorption properties. Magnetic organofunctionalized mesoporous silicas with different morphologies were prepared: ordered mesoporous silica MCM-48 and MCM-41, as well as spherical nanoparticles of mesoporous silica (NPSiO2). The formation of ordered mesoporous silica begins with the preparation of a CTAB template on which silica is deposited/formed to produce MCM-41 and MCM-48 materials. The CTAB concentration must be carefully controlled since colloidal structures with different morphologies can be generated by varying this parameter. The FTIR, XRD and N2 sorption spectroscopy analyzes confirmed the preparation of ordered mesoporous silica materials with a gyroid 3D (MCM-48), or hexagonal type (MCM-41) arrangement respectively with a surface area of 1212 m2.g-1 and 1159 m2.g-1. In addition, the MET images of the MCM-48 material showed mean particle size equal to 116 nm ± 15 nm. To facilitate removal from water, magnetite nanoparticles (SPIONs) were incorporated into the surface of adsorbent materials. The typical removal time was determined to be 1 minute. The organofunctionalization of the silica with octadecylsilane (C18), octylsilane (C8) and diphenylsilane (Ph2) was confirmed by FTIR spectroscopy and thermogravimetric analysis demonstrating the presence and allowing the determination of the mass percentage of the organic fraction in each type of mesoporous silica. Using commercial silica gel (Silica) as reference, the adsorption properties toward BTEX in water were compared when the functionalizing agent is C8, C18 or Ph2. The results indicated that the adsorption capacities, according to the Langmuir model, decrease in the following order C8 ≥ C18 >> Ph2. From this, the adsorption properties of the C8 functionalized silicas were compared showing that the adsorption capacities according to the Langmuir model decrease in the following order: MCM-48 > Silica > NPSiO2 > MCM-41. The organofunctionalized nanocomposite MCM48-C8/SPION, exhibiting the best adsorption properties, was used in magnetic solid phase extraction (m-SPE) of BTEX from gas station water. Only 30 mg of adsorbent, 5 min of contact with the BTEX solution, 1 min to remove the adsorbent and 1 min for extraction were enough for concentration/recovery of BTEX in water by m-SPE technique suitable for quantitative analysis, in this case by CG-MS.

Nesse trabalho de duas partes, colunas monolíticas poliméricas foram aplicadas em extração em fase sólida e em nanocromatografia capilar, duas das suas mais importantes aplicações. Na primeira parte foi desenvolvido um monolito para extração em fase sólida dos metais Cd(II), Pb(II) e Cu(II), que foi acoplada on-line com detecção eletroquímica com o auxílio de instrumentação de análise por injeção sequencial (SIA). A coluna usada como suporte sólido para extração em fase sólida foi obtida com a copolimerização entre formador de ligação cruzada etileno dimetacrilato (EDMA) e monômero funcional glicidil metacrilato (GMA), preparada a partir de uma mistura reacional composta de 30% GMA, 10% EDMA, 5% H2O, 35% n-propanol e 20% 1,4- butanodiol, aquecida durante 24 horas à 60°C. Essa composição e condições de polimerização favoreceram a permeabilidade do monolito, o que foi necessário para o acoplamento no SIA. Após a obtenção do monolito base o mesmo foi modificado pela reação do anel epóxi do grupo GMA com ácido iminodiacético (IDA) para garantir propriedades de quelação de metais e maior capacidade de adsorção para a coluna. O monolito foi caracterizado com imagens de microscopia de varredura eletrônica (MEV) e a capacidade de extração foi de 4,4 ± 0,3 mg Cu(II) m-1 obtida com curvas de breakthrough. O método de determinação on-line dos metais operado por SIA, que executou as etapas de carregamento de amostra, limpeza da coluna, eluição dos analitos e recondicionamento dos sítios ativos teve frequência amostral de 6,8 injeções por hora. Os limites de detecção (LD) e quantificação (LQ) para o método foram, respectivamente, de 1,0 e 3,3 µg L-1 para o Cd(II), 0,7 e 2,2 µg L-1 para o Pb(II) e 0,5 e 1,8 µg L-1 para o Cu(II). O método foi aplicado na determinação dos metais em diferentes matrizes de águas naturais, sendo encontrado Cu(II) em algumas amostras. A exatidão do método foi avaliada com estudos de adição e recuperação nessas águas, obtendo-se valores entre 75,5 e 116,6%. Na segunda parte do trabalho foi utilizada uma coluna polar composta da sulfobetaína zwitteriônica N,N-dimetil-N-metacriloil-oxietil-N-(3-sulfopropil) amônio betaína (MEDSA) e do formador de ligações cruzadas dioxietil dimetacrilato (DiEDMA) em Nanocromatografia de Interação Hidrofílica (HILIC) para fazer a separação de Dopamina, Epinefrina, Norepinefrina, L-DOPA, Tiramina, DOPAC e Ácido Homovanílico, neurotransmissores, alguns de seus metabólitos e precursores, compostos polares de baixa massa molecular. A seletividade cromatográfica da coluna foi altamente dependente da composição da fase móvel aquosa:orgânica, apresentando um mínimo de retenção na transição do mecanismo HILIC para a fase reversa (RP). Ajustando os dados experimentais de fatores de retenção em função da composição da fase móvel com o modelo de retenção duplo foi possível prever qual composição de fase móvel promoveria a separação dos analitos da mistura, que foi atingida em torno de 85% acetonitrila e 15% H2O. A coluna foi modificada com o grupo zwitteriônico 2-metacriloil-oxietil fosforilcolina (MPC) por UV grafting e a modificação da metade do comprimento da coluna durante 30 minutos de exposição UV levou às mudanças na seletividade cromatográfica. / In this two parts work, polymeric monolithic columns were applied in solid phase extraction and in capillary nanochromatography, two of their most important applications. In the first part, a monolith for solid phase extraction of Cd(II), Pb(II) and Cu(II) metals was developed and coupled online with electrochemical detection with the aid of sequential injection analysis instrumentation (SIA). The column used as a solid support for solid phase extraction was obtained by copolymerization between the crosslinker ethylene dimethacrylate (EDMA) and the functional monomer glycidyl methacrylate (GMA), prepared from a reaction mixture composed of 30% GMA, 10% EDMA, 5% H2O, 35% n-propanol and 20% 1,4-butanediol, heated at 60 ° C for 24 hours. This composition and polymerization conditions favored monoliths permeability, which was required for the SIA coupling. After obtaining the base monolith, it was modified by reaction of the epoxy ring of the GMA group with the iminodiacetic acid (IDA) to guarantee metals chelating properties and increase adsorption capacity for the column. The monolith was characterized by scanning electron microscopy (SEM) images and extraction capacity was 4.4 ± 0.3 mg Cu(II) m-1, obtained from breakthrough curves. The method for online determination of metals operated by SIA, which performed the steps of sample loading, column cleaning, analyte elution and reconditioning of active sites had a sampling throughput of 6.8 injections per hour. The limits of detection (LD) and quantification (LQ) for the method were, respectively, 1.0 and 3.3 µg L-1 for Cd(II), 0.7 and 2.2 µg L-1 for the Pb(II) and 0.5 and 1.8 µg L-1 for Cu(II). The method was applied for the determination of metals in different natural water matrices, finding Cu(II) in some samples. The accuracy of the method was evaluated with addition and recovery studies in these waters, finding recoveries between 75.5 and 116.6%. In the second part of the work, a polar column composed of the zwitterionic sulfobetaine N,N-dimethyl-N-methacryloyloxyethyl-N-(3-sulfopropyl) ammonium betaine (MEDSA) and the cross-linker dioxyethyl dimethacrylate (DiEDMA) was used in Hydrophilic Interaction Nanocromatography (HILIC) to separate Dopamine, Epinephrine, Norepinephrine, L-DOPA, Tyramine, DOPAC and Homovanilic Acid, neurotransmitters, some of its metabolites and precursors, which are polar compounds of low molecular mass. The chromatographic selectivity of the column was highly dependent on the composition of the aqueous:organic mobile phase, showing a minimum retention at the transition from the HILIC to the reverse phase (RP) mechanism. By adjusting the experimental data of retention factors as a function of mobile phase composition with the double retention model it was possible to predict which mobile phase composition would promote the separation of the mixed analytes, which was achieved around 85% acetonitrile and 15% H2O. The column was modified with the 2-methacryloyl oxyethyl phosphorylcholine (MPC) zwitterionic group by UV grafting and the modification of half columns length during 30 minutes of UV exposure led to changes in the chromatographic selectivity.

No presente estudo, duas espécies de fungos isoladas do ambiente marinho tiveram seus extratos brutos ativos contra Staphylococcus aureus e Candida albicans para uma espécie de P. citrinum e, atividade citotóxica e contra Mycobacterium tuberculosis para uma espécie de P. oxalicum. Estas foram estudadas com a finalidade de otimizar suas condições de crescimento para produção de metabólitos secundários. Foram realizadas análises multivariadas utilizando planejamento fatorial fracionário. Foram obtidas duas condições ótimas de crescimento para as duas linhagens de Penicillium. O crescimento em maior volume em condições de cultura otimizadas para P. oxalicum permitiu observar a presença de três metabólitos secundários no extrato do meio de cultura. Dois puderam ser isolados e identificados: a meleagrina 52 e a oxalina 26. A metodologia utilizada para se obter uma maior quantidade de metabólitos secundários proporcionou, ainda, o incremento em cerca de 150% na área do pico da oxalina. A partir do crescimento em maior volume em condições de cultura otimizadas para P. citrinum foi possível observar presença de pelo menos onze diferentes metabólitos na análise dos extratos obtidos do meio de cultura. Foi possível identificar e isolar quatro compostos já conhecidos: a (8E)-1-(2,3-diidropirrol-1-il)-2-metildec-8-eno-1,3-diona 56; a 1-(2,3-diidropirrol-1-il)-2-metildecano-1,3-diona 58; a 2-((E)-hept-5-enil)-6,7,8,8a-tetraidro-3-metilpirrolo[2,1-b][1,3]oxazin-4-ona 59 e a citrinina 31. Também foram isolados dois novos alcalóides indólicos contendo um grupo nitro na molécula que foram nomeadas de citrinalinas A 60 e B 62. Foi realizado, também, um estudo com P. citrinum visando a maior produção das citrinalinas, que possibilitou o incremento na produção da citrinalina B. / In this study, two species of fungi isolated from the marine environment had their active extracts against Staphylococcus aureus and Candida albicans to a strain of P. citrinum, and activity cytotoxic and against Mycobacterium tuberculosis to a strain of P. oxalicum. This studied aims the optimization their growth conditions for the production of secondary metabolites. Multivariate analysis using a fractional factorial design were used to establish optimal growth conditions for both Penicillium strains. Two optimal growth conditions were obtained for both Penicillium strains. A largest growth volume of P. oxalicum using optimized conditions enabled the detection of three secondary metabolites in the culture media crude extract. Two of such compounds were isolated and identified: meleagrin 52 and oxaline 26. The methodology used to increase the production of secondary metabolites by P. citrinum enabled an increase of 150% in the peak area of oxaline. A largest growth volume of P. citrinum led to the detection of eleven different metabolites in the culture media. Four of these compounds were isolated and identified as the known (8E)-1-(2,3-dihydropyrrol-1-yl)-2-methyldec-8-ene-1,3-dione 56; the 1-(2,3-dihydropyrrol-1-yl)-2-methyldecane-1,3-dione 58; the 2-((E)-hept-5-enyl)-6,7,8,8a-tetrahydro-3-methylpyrrolo[2,1-b][1,3]oxazin-4-one 59 and citrinin 31. Two new indole alkaloids containing a nitro group were also isolated and identified, named citrinalins A 60 and B 62. A further study with P. citrinum aiming an enhanced production of citrinalins allowed a significant increase in the production of citrinalin B.

A contaminação de aguas pela mistura Benzeno, Tolueno, Etilbenzeno e Xilenos (BTEX) vem gerando a necessidade do desenvolvimento de metodologias altamente eficientes na remoção de poluentes e de metodologias analíticas para monitoramento ambiental suficientemente sensíveis, seletivos, reprodutíveis e rápidos. Nesse contexto, adsorventes com propriedades magnéticas aparecem como alternativas eficientes, de baixo custo e de fácil automação, inclusive possibilitando o desenvolvimento de metodologia analítica baseada na extração em fase sólida magnética (m-SPE), que vem ganhando interesse crescente por permitir extração rápida e análise efetiva dos poluentes com alta sensibilidade. A busca por adsorventes adequados exige o estudo de materiais com grande área superficial, funcionalizáveis e estáveis como as sílicas, mais especificamente uma comparação entre os tipos de sílica e do tipo de agente funcionalizante nas propriedades de adsorção/dessorção. Sílicas mesoporosas oraganofuncionalizas magnéticas com diferentes morfologias foram preparadas: sílica mesoporosa ordenada MCM-48 e MCM-41, bem como nanoparticulas esféricas de sílica mesoporosa (NPSiO2). A formação da silica mesoporosa ordenada começa com a preparação de um template de CTAB sobre o qual são depositados/formados os materiais MCM-41 e MCM-48. A concentração de CTAB deve ser controlada com cuidado pois estruturas com diferentes morfologias podem ser geradas variando-se esse parâmetro. As análises de espectroscopia FTIR, DRX e sorção de N2 revelaram que os materiais preparados são sílicas mesoporosas ordenadas com arranjo tipo giroide 3D (MCM-48) ou do tipo hexagonal (MCM-41) com área superficial respectivamente de 1212 m2.g-1 e 1159 m2.g-1. Além disso, as imagens de MET do material MCM-48 mostraram tamanho médio de partícula igual a 116 nm ± 15 nm. Para facilitar a remoção do adsorvente, nanopartículas de magnetita (SPION) foram incorporadas na superfície dos materiais adsorventes. O tempo de remoção típico foi determinado como sendo de 1 minuto. A organofuncionalização da sílica com octadecilssilano (C18), octilssilano (C8) e difenilssilano (Ph2) foi confirmada por espectroscopia FTIR e análise termogravimétrica demostrando a presença e a percentagem em massa dos grupos orgânicos em cada tipo de sílica mesoporosa. Usando como referência sílica gel 60 comercial (Sílica), foram comparadas as propriedades de adsorção frente a BTEX em agua, quando o agente funcionalizante é C8, C18 ou Ph2. Os resultados indicaram que as capacidades de adsorção, segundo o modelo de Langmuir, seguem a seguinte ordem C8≥C18>>Ph2. A partir disso, as propriedades de adsorção das demais sílicas funcionalizadas com C8 foram comparadas determinando-se que as capacidades de adsorção, segundo o modelo de Langmuir, estão na seguinte ordem: MCM-48>Sílica>NPSiO2>MCM-41. O nanocompósito organofuncionalizado MCM48-C8/SPION, que mostrou as melhores propriedades de adsorção, foi usado para a extração em fase sólida magnética (m-SPE) de BTEX em agua de posto de gasolina. Verificou-se que apenas 30 mg de adsorvente, 5 min de contato com a solução de BTEX, 1 min para remoção do adsorvente e 1 min para a extração foram suficientes para concentração/recuperação de BTEX de agua pela técnica de m-SPE, viabilizando a análise quantitativa, no caso por CG-MS. / The contamination of water bodies by Benzene, Toluene, Ethylbenzene and Xylenes (BTEX) has prompted the development of more efficient methodologies for their removal and the development of sufficiently sensitive, selective, reproducible and fast analytical methods for environmental monitoring. In this context, adsorbent materials with magnetic properties appear as efficient, low cost and easy automation alternatives, including the development of analytical methods based on magnetic solid phase extraction (m-SPE), which has gaining increasing interest since allows rapid extraction and effective analysis of pollutants with high sensitivity. The search for suitable adsorbents requires the study of materials with large surface area, functionalizable and stable as the silica\'s family, more specifically a comparison between the types of silica and the type of functionalizing agent on their adsorption/desorption properties. Magnetic organofunctionalized mesoporous silicas with different morphologies were prepared: ordered mesoporous silica MCM-48 and MCM-41, as well as spherical nanoparticles of mesoporous silica (NPSiO2). The formation of ordered mesoporous silica begins with the preparation of a CTAB template on which silica is deposited/formed to produce MCM-41 and MCM-48 materials. The CTAB concentration must be carefully controlled since colloidal structures with different morphologies can be generated by varying this parameter. The FTIR, XRD and N2 sorption spectroscopy analyzes confirmed the preparation of ordered mesoporous silica materials with a gyroid 3D (MCM-48), or hexagonal type (MCM-41) arrangement respectively with a surface area of 1212 m2.g-1 and 1159 m2.g-1. In addition, the MET images of the MCM-48 material showed mean particle size equal to 116 nm ± 15 nm. To facilitate removal from water, magnetite nanoparticles (SPIONs) were incorporated into the surface of adsorbent materials. The typical removal time was determined to be 1 minute. The organofunctionalization of the silica with octadecylsilane (C18), octylsilane (C8) and diphenylsilane (Ph2) was confirmed by FTIR spectroscopy and thermogravimetric analysis demonstrating the presence and allowing the determination of the mass percentage of the organic fraction in each type of mesoporous silica. Using commercial silica gel (Silica) as reference, the adsorption properties toward BTEX in water were compared when the functionalizing agent is C8, C18 or Ph2. The results indicated that the adsorption capacities, according to the Langmuir model, decrease in the following order C8 ≥ C18 >> Ph2. From this, the adsorption properties of the C8 functionalized silicas were compared showing that the adsorption capacities according to the Langmuir model decrease in the following order: MCM-48 > Silica > NPSiO2 > MCM-41. The organofunctionalized nanocomposite MCM48-C8/SPION, exhibiting the best adsorption properties, was used in magnetic solid phase extraction (m-SPE) of BTEX from gas station water. Only 30 mg of adsorbent, 5 min of contact with the BTEX solution, 1 min to remove the adsorbent and 1 min for extraction were enough for concentration/recovery of BTEX in water by m-SPE technique suitable for quantitative analysis, in this case by CG-MS.

Nesse trabalho de duas partes, colunas monolíticas poliméricas foram aplicadas em extração em fase sólida e em nanocromatografia capilar, duas das suas mais importantes aplicações. Na primeira parte foi desenvolvido um monolito para extração em fase sólida dos metais Cd(II), Pb(II) e Cu(II), que foi acoplada on-line com detecção eletroquímica com o auxílio de instrumentação de análise por injeção sequencial (SIA). A coluna usada como suporte sólido para extração em fase sólida foi obtida com a copolimerização entre formador de ligação cruzada etileno dimetacrilato (EDMA) e monômero funcional glicidil metacrilato (GMA), preparada a partir de uma mistura reacional composta de 30% GMA, 10% EDMA, 5% H2O, 35% n-propanol e 20% 1,4- butanodiol, aquecida durante 24 horas à 60°C. Essa composição e condições de polimerização favoreceram a permeabilidade do monolito, o que foi necessário para o acoplamento no SIA. Após a obtenção do monolito base o mesmo foi modificado pela reação do anel epóxi do grupo GMA com ácido iminodiacético (IDA) para garantir propriedades de quelação de metais e maior capacidade de adsorção para a coluna. O monolito foi caracterizado com imagens de microscopia de varredura eletrônica (MEV) e a capacidade de extração foi de 4,4 ± 0,3 mg Cu(II) m-1 obtida com curvas de breakthrough. O método de determinação on-line dos metais operado por SIA, que executou as etapas de carregamento de amostra, limpeza da coluna, eluição dos analitos e recondicionamento dos sítios ativos teve frequência amostral de 6,8 injeções por hora. Os limites de detecção (LD) e quantificação (LQ) para o método foram, respectivamente, de 1,0 e 3,3 µg L-1 para o Cd(II), 0,7 e 2,2 µg L-1 para o Pb(II) e 0,5 e 1,8 µg L-1 para o Cu(II). O método foi aplicado na determinação dos metais em diferentes matrizes de águas naturais, sendo encontrado Cu(II) em algumas amostras. A exatidão do método foi avaliada com estudos de adição e recuperação nessas águas, obtendo-se valores entre 75,5 e 116,6%. Na segunda parte do trabalho foi utilizada uma coluna polar composta da sulfobetaína zwitteriônica N,N-dimetil-N-metacriloil-oxietil-N-(3-sulfopropil) amônio betaína (MEDSA) e do formador de ligações cruzadas dioxietil dimetacrilato (DiEDMA) em Nanocromatografia de Interação Hidrofílica (HILIC) para fazer a separação de Dopamina, Epinefrina, Norepinefrina, L-DOPA, Tiramina, DOPAC e Ácido Homovanílico, neurotransmissores, alguns de seus metabólitos e precursores, compostos polares de baixa massa molecular. A seletividade cromatográfica da coluna foi altamente dependente da composição da fase móvel aquosa:orgânica, apresentando um mínimo de retenção na transição do mecanismo HILIC para a fase reversa (RP). Ajustando os dados experimentais de fatores de retenção em função da composição da fase móvel com o modelo de retenção duplo foi possível prever qual composição de fase móvel promoveria a separação dos analitos da mistura, que foi atingida em torno de 85% acetonitrila e 15% H2O. A coluna foi modificada com o grupo zwitteriônico 2-metacriloil-oxietil fosforilcolina (MPC) por UV grafting e a modificação da metade do comprimento da coluna durante 30 minutos de exposição UV levou às mudanças na seletividade cromatográfica. / In this two parts work, polymeric monolithic columns were applied in solid phase extraction and in capillary nanochromatography, two of their most important applications. In the first part, a monolith for solid phase extraction of Cd(II), Pb(II) and Cu(II) metals was developed and coupled online with electrochemical detection with the aid of sequential injection analysis instrumentation (SIA). The column used as a solid support for solid phase extraction was obtained by copolymerization between the crosslinker ethylene dimethacrylate (EDMA) and the functional monomer glycidyl methacrylate (GMA), prepared from a reaction mixture composed of 30% GMA, 10% EDMA, 5% H2O, 35% n-propanol and 20% 1,4-butanediol, heated at 60 ° C for 24 hours. This composition and polymerization conditions favored monoliths permeability, which was required for the SIA coupling. After obtaining the base monolith, it was modified by reaction of the epoxy ring of the GMA group with the iminodiacetic acid (IDA) to guarantee metals chelating properties and increase adsorption capacity for the column. The monolith was characterized by scanning electron microscopy (SEM) images and extraction capacity was 4.4 ± 0.3 mg Cu(II) m-1, obtained from breakthrough curves. The method for online determination of metals operated by SIA, which performed the steps of sample loading, column cleaning, analyte elution and reconditioning of active sites had a sampling throughput of 6.8 injections per hour. The limits of detection (LD) and quantification (LQ) for the method were, respectively, 1.0 and 3.3 µg L-1 for Cd(II), 0.7 and 2.2 µg L-1 for the Pb(II) and 0.5 and 1.8 µg L-1 for Cu(II). The method was applied for the determination of metals in different natural water matrices, finding Cu(II) in some samples. The accuracy of the method was evaluated with addition and recovery studies in these waters, finding recoveries between 75.5 and 116.6%. In the second part of the work, a polar column composed of the zwitterionic sulfobetaine N,N-dimethyl-N-methacryloyloxyethyl-N-(3-sulfopropyl) ammonium betaine (MEDSA) and the cross-linker dioxyethyl dimethacrylate (DiEDMA) was used in Hydrophilic Interaction Nanocromatography (HILIC) to separate Dopamine, Epinephrine, Norepinephrine, L-DOPA, Tyramine, DOPAC and Homovanilic Acid, neurotransmitters, some of its metabolites and precursors, which are polar compounds of low molecular mass. The chromatographic selectivity of the column was highly dependent on the composition of the aqueous:organic mobile phase, showing a minimum retention at the transition from the HILIC to the reverse phase (RP) mechanism. By adjusting the experimental data of retention factors as a function of mobile phase composition with the double retention model it was possible to predict which mobile phase composition would promote the separation of the mixed analytes, which was achieved around 85% acetonitrile and 15% H2O. The column was modified with the 2-methacryloyl oxyethyl phosphorylcholine (MPC) zwitterionic group by UV grafting and the modification of half columns length during 30 minutes of UV exposure led to changes in the chromatographic selectivity.

"Ghadiri reported the first synthetic peptide nanotubue in 1993, which has triggered extensive studies on peptide-based nanotubes and their potential application in molecular wires, catalysts and novel drug delivery vehicles. Our concerns focus on chromophore-modified cyclic peptides, which open a new way to design and synthesize novel nanoscale electronic or photonic devices, and are expected to provide the highly efficient electron and energy transfer that such devices require. This research concerned the design and synthesis of chiral a-amino acids with specific chromophores, including N-ethyl-3-carbazolylalanine and 9-anthrylalanine, and an 8-mer linear peptide (H-Aib-Car-Aib-Phe-Aib-Bpa-Aib-Phe-OH) and its corresponding cyclic peptide cyclo(Aib-Car-Aib-Phe-Aib-Bpa-Aib-Phe) that incorporate the N-ethyl-3-carbazolylalanine. This thesis describes the relevant background, synthetic strategies, experiments and results in detail. The carbazole derivatives were found to be very labile to strong acid, which might have caused self-condensation. In order to avoid the formation of acid-derived side-products, the Wittig-Horner reaction was used successfully in preparation of N-protected-3-(N'-ethyl-3-carbazolyl)-DL-alanine methyl ester. Dual enzymatic hydrolyses were developed to produce the chiral amino acids with high enantiomeric excess. ChiroCLEC-BL was used to selectively hydrolyze the N-acetyl-L-amino acid methyl ester, while amanoacylase was adopted to remove the acetyl group from the resulting N-acetyl-L-amino acid. Two model peptides were synthesized, a 4-mer peptide (H-Car-D-Ala-Bpa-D-Ala-OH) via the Boc-strategy, and an 8-mer peptide (H-Ala-D-Ala-Npa-D-MeAla-Ala-D-Ala-Bpa-D-Ala-OH) by the Fmoc-strategy. Eventually, the target linear peptide was synthesized via the Fmoc-strategy and then cyclized in solution."

A series of bicyclic peptides have been designed and synthesized to provide ammonium ion complexation sites via hydrogen bonding in a tetrahedral geometry. Molecular modeling dynamics and electrostatics studies indicate that target compounds 1d-6d may provide better selectivity for ammonium ions over potassium ions than the ammonium ionophore currently used for blood analysis applications, nonactin. Attempts to synthesize 1d, cyclo(L-Glu1�D-Val2�L-Ala3�D-Lys4�D-Val5�L-Val6)-cyclo-(1ã-4å), were unsuccessful due to poor solubility of the synthetic intermediates. This led to the design of 2d-6d in which specific amino acid residues were chosen to provide higher solubility. Compound 2d, cyclo(L-Glu1�D-Ala2�D-Ala3�L-Lys4�D-Ala5�L-Ala6)-cyclo-(1ã-4å), was successfully synthesized, but was also too insoluble for characterization or testing in an ion selective electrode (ISE) sensor format. Compound 6d, cyclo(L-Glu1�D-Leu2�Aib3�L-Lys4�D-Leu5�D-Ala6)-cyclo-(1ã-4å), was successfully synthesized and characterized. When 6d was incorporated into an ISE sensor and tested as an ammonium ionophore, results indicated that the bicyclic peptide lacked solubility in the ISE membrane. A 13C-NMR study has been initiated in order to evaluate selectivity of 6d for ammonium over potassium and sodium cations in solution. Preliminary results with the potassium ionophore valinomycin as a control have been completed.

Les variations de température à la surface externe d'une conduite peuvent provoquer la solidification du fluide en écoulement interne, induisant la formation de dépôts solides sur les parois en contact avec le fluide. Ces dépôts peuvent s'avérer néfastes au bon fonctionnement du système intégrant cette conduite ce qui motive l'étude de ces phénomènes physiques afin de comprendre les mécanismes qui les gouvernent et de permettre leur prévention. Ce genre de situations peuvent être rencontrées dans le domaine pétrolier, par exemple lors du transport en pipeline d'huiles chargées de paraffines, d'hydrates ou d'asphaltènes ; dans le domaine agroalimentaire pour la circulation de produits liquides dans des tubes refroidis ou bien tout simplement pour des canalisations d'eau subissant un refroidissement. Dans la majorité des cas le fluide en écoulement dans les conduites pétrolières est un matériau à changement de phase (MCP) complexe et sa composition multiple avec des interactions entre la rhéologie, la constitution et la température impactant la thermo-hydrodynamique de l'écoulement et la cinétique de transition de phase. Dans le cadre de cette thèse nous proposons de nous pencher sur ces aspects par voie de modélisation. Dans la première partie de ce travail, nous avons développé un modèle physique basé sur la méthode enthalpique pour étudier l’impact de la convection naturelle sur des écoulements et des transferts thermiques avec transition de phase solide liquide dans différentes géométries (cavité carré, cylindre, sphère, autour d’un faisceau de cylindre, …). L'effet du maillage et de l'ordre de précision des schémas numérique est aussi présenté. Le même modèle a été utilisé pour analyser la cristallisation d’un mélange de deux paraffines dans des cellules calorimétriques (Differential Scanning Calorimetry). Pour cette étude, le modèle a été validé à l’aide des résultats expérimentaux de la technique DSC. Le problème de l’écoulement d’un mélange de deux paraffines dans une conduite cylindrique a été aussi abordé afin de prédire la cristallisation du mélange sur la paroi interne de la conduite. Une étude paramétrique a été effectuée pour analyser l’influence de différents paramètres (nombre de Reynolds, concentration initiale de la solution binaire, température de la paroi, …) sur la cinétique de la cristallisation du mélange. La deuxième partie de la thèse a été consacrée à l’étude de l’écoulement avec changement de phase liquide-solide d’un brut paraffinique dans des conduites pétrolières. En effet, la cristallisation des paraffines dans les bruts engendre un équilibre phase thermodynamique liquide/solide. Un modèle thermodynamique rendant compte de cet équilibre a été développé (et validé à l’aide de résultats expérimentaux disponible dans la littérature). Ce modèle nous a permis de prédire la température de cristallisation commençante (Wax Appearance Temperature), ainsi que la quantité de paraffines cristallisées. Ce modèle thermodynamique a été couplé avec un modèle physique reposant sur les équations de conservation de la masse, de la quantité de mouvement, de l'énergie et des espèces pour décrire l’écoulement d’un brut paraffinique avec changement de phase liquide-solide dans des conduites pétrolières. Le modèle physique a été validé à l’aide de résultats expérimentaux disponibles dans la littérature. / Temperature change at the outer surface of a pipe can cause solidification of the fluid flowing internally, inducing the formation of solid deposits on the walls in contact with the fluid. This kind of phenomena can be encountered in many situations in the industrial context such as petroleum industries, for example when transporting pipeline oils with paraffins, hydrates or asphaltenes; food industry for the flow of liquids in cooled tubes or simply for water pipes undergoing cooling.The rheology of the transported fluid, its composition and temperature are among the key factors that influence the thermo-hydrodynamics of the flow and the kinetics of the formation of the deposits. The analysis of their impact is required to enhance the understanding of these mechanisms in order to avoid their undesirable effects as fouling or complete blockage of pipes.In this thesis we propose to study these mechanisms by numerical modelling. We will focus on the modelling of phase change and especially on the description of liquid-solid interfaces by models able to integrate the thermodynamics of physical phenomena such as diffuse interface methods. We seek the two-dimensional numerical resolution of the equations of flow, heat and mass transfer while taking into account the coupling between rheology, composition and temperature in the liquid phase as well as at the interface. The work will be undertaken in the basis of the in-house computational fluid dynamics (CFD) code developed in the laboratory.