Orientador: Lauro Tatsuo Kubota / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-14T02:29:01Z (GMT). No. of bitstreams: 1 Santos_WilneydeJesusRodrigues_D.pdf: 6401846 bytes, checksum: 72d1c8253a6ec5d1d17792b0bd34ca39 (MD5) Previous issue date: 2009 / Resumo: O presente trabalho descreve as aplicações de nanoreatores biomiméticos à peroxidase baseados em MIP ("Molecularly Imprinted Polymers") como uma ferramenta promissora para determinação de substâncias de grande interesse biológico e ambiental, tais como os compostos fenólicos (4-aminofenol e serotonina). Neste sentido, a síntese dos MIPs foi baseada na polimerização convencional em "bulk". Cada polímero foi sintetizado a partir do ácido metacrílico (monômero funcional), etileno glicoldimetilacrilato (reagente de ligação cruzada), 2¿2-azo-bis-isobutironitrila (iniciador radicalar), em presença de Fe(III)protoporfrina(IX) (hemina) como centro catalítico, o qual é responsável pela mimetização do sítio ativo da peroxidase, criando portanto, um polímero com impressão molecular cataliticamente ativo para o reconhecimento do 4-aminofenol e serotonina (moléculas molde). Além disso, a fim de avaliar a seletividade do material, foram preparados, paralelamente, polímeros sem a impressão molecular (NIP Non Imprinted Polymers) e também na ausência de hemina. Os MIPs foram caracterizados pelas técnicas de espectroscopia no infravermelho, área superficial específica, volume específico dos poros, análise termogravimétrica, microscopia eletrônica de varredura. Parâmetros cinéticos, incluindo valores de velocidade máxima, Vmax e constante aparente de Michaelis¿Menten, Km foram obtidas pelo gráfico de Lineweaver-Burk. Para aplicação analítica, em amostras de água e soro sanguíneo, sistemas amperométricos foram otimizados através de análise multivariada / Abstract: The present work describes the applications of biomimetic nanoreactor to the based peroxidase in molecularly imprinted polymers (MIP) as a promising tool for determination of substances of high biological and environmental interest, such as phenolic compounds (4-aminophenol and serotonin). In this sense, the synthesis of MIPs was based on the conventional polymerization in bulk. Each polymer was synthesized from methacrylic acid (functional monomer), ethylene glycol dimethacrylate (cross-linking reagent), 2,2'-azobis-isobutyronitrile (initiator), in the presence of Fe(III)protoporphyrin(IX) (hemin) as a catalytic center, which is responsible for the mimic of the active site of peroxidase, creating therefore, a molecularly imprinted polymer active catalytically for the recognition of the 4-aminophenol and serotonin (template molecules). Furthermore, in order to evaluate the selectivity of the material, were prepared, parallel, polymers without the molecular impression (NIP - Non imprinted polymers) and also in the hemin absence. The MIPs were characterized by the techniques of infrared spectroscopy, specific surface area, specific pore volume, thermogravimetric analysis, scanning electron microscopy. Kinetic parameters, including values for maximum rate, Vmax and Michaelis-Menten apparent constant, Km were obtained from Lineweaver-Burk plots. For analytical application, in samples of water and blood serum, amperometric systems were optimized through multivariate analysis / Doutorado / Quimica Analitica / Doutor em Ciências

Orientador: Susanne Rath / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-10T22:20:57Z (GMT). No. of bitstreams: 1 Pereira_LeandroAlves_M.pdf: 1182437 bytes, checksum: 9e5bb63e48650f93fbbd8632bfc95f93 (MD5) Previous issue date: 2008 / Resumo: Resíduos de agrotóxicos presentes em alimentos podem exceder os limites máximos de resíduos, quando as boas práticas agrícolas não são respeitadas. Conseqüentemente, a determinação dos resíduos de agrotóxicos é extremamente importante para avaliar o uso apropriado dessas substâncias e os riscos à saúde humana decorrentes da sua presença nos alimentos. A determinação de resíduos de agrotóxicos em alimentos requer etapas de preparo de amostras que consistem, geralmente de etapas de extração, remoção de interferentes e concentração do analito anterior análise cromatográfica. Para tanto, tem sido largamente empregada a extração em fase sólida. O objetivo do presente trabalho foi a síntese e caracterização de polímeros de impressão molecular (MIP) para uso em cartuchos de extração em fase sólida, visando a determinação de fenitrotiona (FNT) em tomates. O polímero foi sintetizado a partir do ácido metacrílico (monômero funcional), etileno glicoldimetilacrilato (reagente de ligação cruzada), 2'2azo-bis-iso-butironitrila (iniciador radicalar) em diclorometano (solvente porogênico), usando a FNT como molécula molde. Também foi sintetizado um polímero de controle (NIP). O MIP foi caracterizado por técnicas de infravermelho de transformada de Fourier, ressonância magnética nuclear do estado sólido, microscopia de varredura eletrônica e porosimetria de sorção de nitrogênio. O modelo de Langmuir-Freundlich foi o que apresentou o melhor ajuste para descrever a adsorção da FNT no polímero. O MIP foi empregado em cartuchos de extração em fase sólida e as etapas de condicionamento, carregamento, lavagem e eluição otimizadas. A extração em fase sólida molecularmente impressa foi aplicada na determinação de FNT em amostras de tomates, usando a cromatografia líquida de alta eficiência associada a um detetor de arranjo de diodos. A eficiência de extração, para amostras branco de tomates fortificadas com 5mg g de FNT, foi de 65 %. Nenhum interferente foi observado nos cromatogramas no tempo de retenção da FNT, indicando a seletividade do polímero / Abstract: Pesticide residues present in food can exceed maximum residue level when good agricultural practices are not followed. Consequently, the determination of pesticide residues is extremely important to evaluate the appropriate use of theses substances and risks to human health due to their presence in food. The determination of pesticide residues in food requires sample preparation steps that consist mainly of extraction, clean-up, and concentration of the analyte prior to chromatographic quantitation.. For this purpose, solid-phase extraction has been widely employed. The aims of this work were the synthesis and characterization of a molecularly imprinted polymer (MIP) to be employed as a sorbent in solid phase extraction cartridges for the determination of fenitrothiom (FNT) in tomatoes. The polymer was synthesized using FNT as the template molecule, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linking monomer, and 2,2-azobis-isobutyronitrile as the initiator. Dichloromethane was used as the porogenic solvent. Also, a non-imprinted polymer was synthesized. The MIP was characterized using the following techniques: FT-IR, NMR, electronic microscopy and BET. The adsorption of FNT on the polymer was fitted to the Langmuir-Freundlich model. The polymer was used in the solid-phase extraction cartridges and the conditioning, sample loading, clean-up and elution steps were optimized. The molecularly imprinted solid phase extraction was used for the determination of FNT in tomatoes, using high performance liquid chromatography with a diode array detector. For extraction efficiency, for a fortified blank tomato sample (5 mg g FNT), was 65 %. No interferences were observed in the chromatograms at the retention time of FNT, indicating the selectivity of the polymer / Mestrado / Quimica Analitica / Mestre em Química

Este trabalho descreve o desenvolvimento de novos métodos cromatográficos em conjunto com técnicas de microextração para determinação de parabenos em produtos cosméticos e leite humano e rifampicina em amostras de plasma. Destaca-se também o desenvolvimento da fase extratora molecularmente impressa para extração em fase sólida (SPE) de parabenos em amostras de leite humano. O capítulo I descreve a avaliação da extração sortiva em barra de agitação (SBSE) em conjunto com a cromatografia líquida (LC) com detecção espectrofotométrica (LC-UV) para análises de parabenos em produtos cosméticos para fins de controle de qualidade. As variáveis do processo de extração SBSE, tais como tempo e temperatura de extração, pH e força iônica da amostra e condições de dessorção foram otimizadas para aumentar a sensibilidade analítica do método e diminuir o tempo de análise. O método SBSE/LC-UV desenvolvido apresentou faixa linear correspondente ao limite de quantificação (LQ) a 2,50 µg. mg-1 e coeficientes de determinação maiores que 0,993. Os valores de coeficiente de variação resultantes das análises de precisão interensaios foram 5,0% para todos os parabenos analisados e a exatidão variou de 90 a 100%. O método desenvolvido foi aplicado para análises de amostras de produtos cosméticos comerciais (cremes hidratantes, antitranspirantes em creme e filtros solares). O método SBSE/LC-UV padronizado e validado resultou nas seguintes vantagens em relação aos métodos convencionais: simplicidade no preparo de amostra, redução do volume de solvente orgânico e da quantidade de amostra utilizada. O capítulo II descreve o desenvolvimento da fase extratora molecularmente impressa para SPE de parabenos em amostras de leite humano e análises por cromatografia em fase líquida com detecção espectrofotométrica (SPE/LC-UV). Os polímeros de impressão molecular, materiais sintéticos baseados em sistemas biomiméticos, foram sintetizados através do processo sol-gel tendo como molde, o benzilparabeno. Após a remoção do molde, cavidades seletivas (sítios de reconhecimento molecular) ao benzilparabeno e análogos estruturais foram reveladas. O método SPE/LC desenvolvido apresentou faixa linear correspondente ao limite de quantificação a 150 ng. mL-1 e coeficientes de determinação 0,992. Os valores de coeficiente de variação resultantes das análises de precisão interensaios foram 13% e a exatidão variou de 86 a 117%. A aplicabilidade do método SPE/LC foi demonstrada através das análises de amostras de leite humano de lactantes. Segundo os parâmetros de validação analítica avaliados, o método padronizado SPE/LC-UV é adequado para análises de parabenos em amostras de leite humano. O capítulo III descreve a avaliação da microextraçao em fase sólida no capilar (in-tube SPME) acoplada à cromatografia líquida (LC) com detecção espectrofotométrica (LC-UV) para análises de rifampicina em amostras de plasma para fins de monitorização terapêutica. As variáveis in-tube SPME, tais como fase estacionária da coluna capilar, volume de amostra, ciclos aspirar/dispensar e vazão foram otimizadas visando obter maior eficiência do processo. O método in-tube SPME/LC desenvolvido apresentou faixa linear correspondente ao limite de quantificação (0,1 µg. mL-1) a 100 µg. mL-1 e coeficientes de determinação igual a 0,998. Os valores de coeficiente de variação resultantes das análises de precisão interensaios foram 2% e a exatidão variou de 83 a 92%. A aplicabilidade do método in-tube SPME/LC, padronizado e validado foi comprovada através das análises de amostras de plasma de pacientes em tratamento com rifampicina. O método in-tube SPME/LC resultou na automação do processo de análise, maior precisão analítica, menor tempo de análise, menor volume de solvente orgânico e de fluido biológico. / This work describes the development of chromatographic methods in combination with microextraction techniques for the determination of parabens in cosmetic and human milk samples and of rifampicin in plasma samples. The design of a molecularly imprinted extraction phase for the solid-phase extraction (SPE) analysis of parabens in human milk samples is also reported. Chapter I describes the evaluation of the stir bar sorptive extraction (SBSE) in combination with liquid chromatography (LC) with UV detection (LC-UV) for the analysis of parabens in cosmetics aiming at quality control. The SBSE variables such as extraction time, temperature, pH of the matrix, ionic strength, and desorption conditions have been optimized, in order to establish the parabens partition equilibrium in a short analysis time. The linear range of the SBSE/LC method lay from LOQ to 2.5 µg. mg-1, with a coefficient of determination higher than 0.993. The interday precision of the SBSE/LC method presented a coefficient of variation lower than 5%, and the accuracy ranged from 90 to 99%. The effectiveness of the proposed method for the analysis of commercial cosmetic products such as body creams, antiperspirant creams, and sunscreens has been proven. Therefore, the combination of SBSE with liquid desorption, followed by LC analysis, provides a simple, and selective tool for the analysis of parabens in cosmetic products using minimized volume of organic solvent as well as very small amount of the target sample. Chapter II presents the development of a molecularly imprinted extraction phase for the SPE analysis of parabens in human milk samples. The molecularly imprinted polymers, which are synthetic materials based on biomimetic systems, were synthesized by the sol-gel technology in the presence of the template (benzilparaben). After template removal, selective cavities (benzilparaben) were revealed for parabens selective extraction. The linear range of the SPE/LC method lay from LOQ to 150 ng. mL-1, with a coefficient of determination higher than 0.992. The interday precision of the SPE/LC method presented a coefficient of variation lower than 13%, and the accuracy ranged from 86 to 117%. The effectiveness of the proposed method for the analysis of human milk samples has been demonstrated. According to the evaluated analytical validation parameters, the SPE/LC-UV method is suitable for the analysis of parabens in human milk samples. Chapter III depicts the evaluation of solid-phase microextraction in the capillary (in-tube SPME) in combination with liquid chromatography (LC) with UV detection (LC-UV) for the analysis of rifampicin in plasma samples for therapeutic drug monitoring. The in-tube SPME/LC method was linear over the LOQ (0.1) to 100 g. mL-1 range, with a linear coefficient value (r2) of 0.998. The inter-assay precision presented coefficient of variation 2%, and the accuracy ranged from 83 to 92%. The effectiveness and practicability of the proposed method have been by analysis of plasma samples from ageing patients undergoing therapy with rifampicin. The in-tube SPME/LC method allowed for automated continuous sample preparation (extraction, concentration, desorption, and injection of analytes) and minimized the analysis time as well as the volumes of organic solvent and biological fluid.

Orientador: Ivo Milton Raimundo Júnior / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-20T16:51:10Z (GMT). No. of bitstreams: 1 Santos_KleciaMoraisdos_D.pdf: 2306751 bytes, checksum: bf7642f623ca7798b881b810cd6dd821 (MD5) Previous issue date: 2012 / Resumo: Neste trabalho diferentes fases sensoras foram desenvolvidas para implementar novas estratégias para a determinação de íons cobre em águas naturais, empregando Espectroscopia Óptica de Emissão em Plasma Induzido por Laser (LIBS) e Espectroscopia de Luminescência. Nas determinações por LIBS, membranas de PVC plastificadas foram empregadas para extração e pré-concentração de íons cobre em meio aquoso, fornecendo curvas analíticas na faixa de 10 mg L - 100mg L (R > 0,90). Esses estudos mostraram que a técnica LIBS é capaz de detectar íons cobre em concentrações da ordem de mg L, indicando que membranas extratoras podem ser aplicadas como uma eficiente estratégia de pré-concentração. Dessa forma, LIBS pode ser considerada como uma potencial e viável ferramenta para determinação de íons Cu(II) em águas. Determinações baseadas em Espectroscopia de Luminescência foram realizadas usando o bis(1,10-fenantrolina)1-(4-hidroxi 3-(1H-imidazol [4,5-f][1,10] rutênio(II) bis hexafluorofosfato ([Ru(phen)2HAIP](PF6)2), que foi imobilizado em membranas de metacrilato, de PVC e iônicas, sol-gel e nanopartículas (NP) de sílica. O reagente luminescente apresenta alta seletividade para íons Cu (II) em solução, enquanto somente as nanopartículas mostraram sensibilidade adequada para esse íon. As nanopartículas de sílica foram sintetizadas através do método Stöber, sendo que o reagente luminescente foi adicionado em diferentes estágios da síntese (0, 3, 6 e 8 horas), a qual foi realizada em um total de 10 horas. A microscopia de transição eletrônica (TEM) mostrou nanopartículas com diâmetros em torno de 10-20 nm. As nanopartículas sintetizadas pela adição do reagente após 8h de síntese apresentaram uma faixa linear entre 2,0-8,0 mmol L, um limite de detecção de 0,30 mmol L, um limite de quantificação de 1,0 mmol L e um tempo de resposta (t90%) < 30 s. A nanopartícula apresentou alta seletividade para íons cobre, não mostrando interferências dos íons Zn(II), Cd(II), Ni(II), Hg(II), Pb(II) e Fe(III). As nanopartículas foram aplicadas para determinação de íons Cu(II) em amostras de água mineral e de torneira que foram enriquecidas com 5,0 e 7,0 mmol L do analito. Recuperações na faixa de 88,1-109,6% foram obtidas, indicando a potencialidade das NPs fluorescentes para determinação de Cu(II) em águas. Além disso, os íons Cu (II) podem ser liberados na NP depois de tratamento ácido, sendo regenerado para um novo conjunto de medidas, tornando o reagente reutilizável, fato que está de acordo com os princípios da Química Verde / Abstract: In this work, different sensing phases were developed to implement new strategies for determination of copper ions in natural waters, employing Laser Induced Breakdown Spectroscopy (LIBS) and Luminescence Spectroscopy. In the determinations by LIBS, plasticized PVC membranes were employed for extraction and pre-concentration of copper ions in aqueous medium, providing analytical curves in the range from 10 mg L to 100mg L (R > 0.90). These studies have shown that LIBS is able to detect copper ions in concentrations as low as mg L, indicating that extraction membranes can be applied as an efficient strategy of pre-concentration. In this way, LIBS can be considered as a potential and feasible tool for Cu(II) determination in waters. Determinations based on luminescence spectroscopy were performed by using the bis(1,10-phenanthroline)1-(4-hydroxy 3-(1H-imidazo [4,5-f][1,10] ruthenium(II) bis(hexafluorophosphate) reagent ([Ru(phen)2HAIP](PF6)2), which was immobilized in methacrylate, PVC and ionic membranes, sol-gel silica and silica nanoparticles (NP). The luminescent reagent presented high selectivity to Cu(II) ions in solution, while only the silica nanoparticles showed adequate sensitivity to this ion. The nanoparticles were synthesized by the Stöber method, being the luminescent reagent added at different stages of the synthesis (0, 3, 6 and 8 hours), which was a performed in a total interval of 10 hours. The transmission electron microscopy (TEM) showed nanoparticles with diameters around 10-20 nm. The nanoparticles synthesized by adding the reagent after 8 hours provided a linear response range from 2.0 to 8.0 mmol L, a detection limit of a 0.30 mmol L, a quantification limit of 1.0 mmol L and response time (t90%) < 30 s. The nanoparticle presented high selectivity for copper ions, showing no interference of Zn(II), Cd(II), Ni(II), Hg(II), Pb(II) and Fe(III) ions. The nanoparticles were applied to determination of Cu(II) ions in mineral and tap water samples, which were spiked with 5.0 and 7.0 mmol L of the analyte. Recovery within 88.1-109.6% were attained, indicating the capability of the fluorescent NPs for Cu(II) determination in waters. In addition, the Cu(II) ions can be released from the NP by acidic treatment, being regenerated for another set of measurements, making the reagent reusable, fact that is in agreement with the principles of Green Chemistry / Doutorado / Quimica Analitica / Doutor em Ciências

Orientador: Douglas Soares Galvão / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-20T20:43:55Z (GMT). No. of bitstreams: 1 Moura_FranciscoAlirioAlmeidaGomesde_M.pdf: 1452512 bytes, checksum: 5bfe0662fc16432eada98d772559aa36 (MD5) Previous issue date: 2012 / Resumo: Nesse estudo, investigamos, utilizando ferramentas computacionais, o problema do desenvolvimento racional de polímeros molecularmente impressos (MIP). Utilizamos vários tipos de simulações moleculares: dinâmica molecular, simulated annealing e método de Monte Carlo para alcançar uma seleção de monômeros funcionais baseada em uma biblioteca de monômeros candidatos para uma dada substância-alvo de interesse. Aplicamos esses métodos à simulação das soluções pré-polimerização para a construção de um MIP para a substância 17ß-estradiol, que é uma molécula orgânica de interesse médico e ambiental. Fomos bem sucedidos em simular a solução pré-polimerização para nove monômeros diferentes e construímos uma lista ordenada de possíveis melhores candidatos dentre esses nove / Abstract: In the present study, we investigated by means of computational tools, the problem of rational design of Molecularly Impressed Polymers (MIP). We used several different types of simulations: molecular dynamics, simulated annealing and Monte Carlo method to achieve a selection of functional monomers based on a library of candidates for the functional monomers for some given target substance of interest. We applied these methods to pre-polimerization solutions for the design of a MIP for the substance 17ß-estradiol, which is an organic molecule of medical and environmental interest. We were successful in simulating the pre-polimerization solutions for nine different monomers and building an ordered list of possible best monomers among these candidates / Mestrado / Física / Mestre em Física

In the present work, molecular dynamics simulations were used to evaluate the molecular interactions in prepolymerization mixtures, as occurring during production of molecularly imprinted polymers. The systems simulated were produced based on earlier studies for reference of results. Four systems were simulated in order to investigate the effect on molecular interactions based upon the choice of porogen (acetonitrile or chloroform) and proton transfers. The systems consisted of phenylalanine anilide as template, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as crosslinker and 2,2’-azobis-(2-methylpropionitrile) as radical initiator, with either acetonitrile or chloroform as porogen. Trajectories from the simulations were evaluated through radial distribution function analysis, grid density analysis and hydrogen bond analysis to investigate molecular interactions and complex formations in the simulated complete prepolymerization mixtures. Focus was on functional monomer-template, crosslinker-template and template-template complex formations. The results showed that the porogen influences molecular interactions in complete prepolymerization mixtures. Formation of higher order complexes was confirmed in all of the systems involving all of the investigated molecular species in the prepolymerization mixtures. The results could also confirm the presence of previously observed complexes between functional monomer and template (2:1 and 1:1 stoichiometry) and the prevalence of template dimerization, as well as a high involvement of crosslinker in complex formation.

Ces travaux de recherches concernent l'association de la technologie des polymères à empreintes moléculaires aux dispositifs acoustiques à onde de Love afin de réaliser un biocapteur dans le cadre d'un projet ANR Tecsan. La première partie de ces travaux de thèse a dressé plus spécifiquement la mise au point d'un protocole de dépôt localisé de polymères imprimés (MIP) et non imprimés (NIP) en films minces compatibles avec la propagation de l'onde élastique. La seconde aprtie des travaux a visé une caractérisation des films et des capteurs ainsi réalisés, par microscopie à balayage et apr mesures de détection sous gaz. Des éléments relatifs aux propriétés mécaniques (porosité, surfaces spécifiques) des MIPs et NIPs, avant extraction de la molécule cible, puis après extraction et après recapture, ont permis de valider le principe du capteur, ouvrant la voie à l'application en milieu liquide. / This work deals with the association of molecularly imprinted polymers technology and Love wave devices in order to develop a biosensor in the frame of ANR project, Tecsan. The first part of this work concerned the development and the validation of a protocol for localized deposition of imprinted (MIP) and non-imprinted (NIP) polymeric thin film compatible with the propagation of acoustic wave. The second part exhibited the cahracterization of the coated sensors, by scanning microscopy and deep gas characterization. The proposed characterization technique gives information on surface morphology and porosity of thin MIP films before extraction of the target molecule, then after extraction and after rebinding. It allowed hence, the validation of the sensor principle. These results constitute a god background for future application in medium liquid.

Alkaloid toxicities negatively impact livestock health and production and are of serious economic concern to animal industries. To date, few strategies have been developed to evaluate alkaloid levels in feed or to counteract alkaloid toxicities. The present research evaluated the applicability of imprinting technology to synthesize polymers that have potential to interact with ergot alkaloids and therefore reduce their bioavailability in the GIT. The studies also evaluated applicability of synthesized polymers for use in the ruminal environment using an in vitro ruminal fermentation model, and for the ability to ameliorate vasoconstriction using ex vivo myographic evaluations. In the first experiment, styrene-based molecularly imprinted polymer (MIP) was synthesized using ergotamine as the imprinting template and evaluated for specificity of adsorption to various ergot alkaloids. Cross reactivity with related alkaloids exists due to similarities in structure and functional groups. Both polymers (MIP and NIP) showed strong adsorption intensity and no difference was observed for estimated maximum adsorption capacity between MIP and NIP. Morphologically, MIP was highly porous with greater surface area than NIP. Solid phase extraction indicated stronger adsorption of MIP than NIP to ergot alkaloids suggesting the potential for MIP as a sorbent material for solid phase extraction (SPE) columns used for sample clean-up prior to HPLC or LC-MS/MS analysis of complex samples. In Experiment 2, methacrylic acid-based polymers were synthesized with ergotamine as a template. Among the 4 alkaloids evaluated for selectivity, adsorption difference between MIP and NIP interacted with alkaloid concentration, although differences were generally consistent across concentrations. Imprinting did not affect lysergol and bromocriptine adsorption, but resulted in higher adsorption to methylergonovine. However, there was no difference between MIP and NIP for adsorption of ergotamine. Hydrophobic interactions and H-bonding were the primary interactive forces between polymers and alkaloid adsorbents. Morphologically, MIP had greater surface area and porosity implying a larger surface for adsorption. In addition to its application as SPE sorbent, this MIP was a suitable candidate for application as a feed adsorbent to reduce the bioavailability of certain alkaloid in the gut. In experiment 3, methacrylic acid-based polymers were evaluated for their effect on in vitro ruminal fermentation. There were no interactions between polymer type and inclusion level, and no differences between polymer types for cumulative gas production or rate of gas production. Total gas production and rate of gas production were unaffected by inclusion level. Polymers did not affect total or individual VFA concentrations, ammonia-N or methane concentration at any inclusion level. However, a logarithmic increase in polymer dose level decreased the pH linearly with maximum depression of 0.24 units. This study indicated that, within the range of expected use levels, polymers were essentially inert and would not be expected to affect ruminal fermentation. In experiment 4, ex vivo myographic bioassays were used to determine the impact of polymers on ergotamine bioavailability. Responses measured in the ex vivo myographic studies had similar trend as the responses generated from in vitro isothermal adsorption studies. Results of that study also showed that ex vivo myographic responses could be predicted from in vitro isothermal adsorption studies with more than 80% accuracy. These studies indicate that synthetic polymers are potentially effective adsorbents to mitigate ergot toxicity with little evidence of substantial differences between MIP and NIP.

Un polymère à empreintes moléculaires (MIP) est un récepteur synthétique supramoléculaire, un matériau possédant des cavités pouvant reconnaître spécifiquement une molécule cible. Il est synthétisé en mettant en contact la molécule cible, avec un mélange de monomères fonctionnels et réticulants qui permettent d'obtenir un réseau polymérique tridimensionnel rigide. L'élimination de la molécule empreinte laissera des sites vides complémentaires de cette dernière. Ces cavités sont maintenant capables de la recapturer spécifiquement. Ces polymères sont utilisés dans les domaines tels que l’extraction en phase solide, la chromatographie d’affinité, la catalyse enzymatique, les biocapteurs et la vectorisation des médicaments. Bien que le concept des MIPs a pour origine les travaux réalisés sur des matériaux sol-gel imprimés dans les années 1930, ces derniers sont restés dans l’ombre jusqu’à l'introduction de polymères organiques imprimés plus versatiles. Par rapport aux MIPs organiques, les MIPs sol-gel présentent quelques avantages comme une plus grande stabilité thermique, une meilleure compatibilité avec l'eau et une plus grande porosité. Dans cette thèse, nous avons développé des MIPs organiques et des MIPs sol-gel pour leur application en cosmétologie et pour la vectorisation de médicaments. Dans la première partie, nous présentons des MIPs pouvant adsorber d’une façon spécifique l’acide oléique (OA), un biomarqueur de l’état pelliculaire sur le cuir chevelu. Pour la préparation des MIPs organiques, nous avons employé plusieurs monomères basiques dont l’acryloylaminobenzamidine (AB), que nous avons tout spécialement synthétisé. Tous les MIPs pouvaient lier l’OA mais beaucoup d’interaction non-spécifique était observé. D’autre part, les MIPs sol-gel présentaient une bonne reconnaissance spécifique et une capacité élevée pour OA; par exemple, un MIP de composition OA:APTES:TEOS = 1:1.6:1.7 pouvait adsorber 625 μmol.g-1 de OA dans le sébum artificiel. Des tests pour capturer l’OA sur le stratum corneum et la peau reconstruite (Episkin) ont également été effectués. La pénétration de l’OA sur les deux types de peau était plus faible en présence de MIP que de NIP. Les MIPs comme matériaux désodorisants font l’objet de la deuxième partie de cette thèse. Des MIPs pouvant adsorber les précurseurs de molécules malodorantes comme les conjugués glutamine des acides (E)-3-méthyl-2-hexénoïque (3M2H) et 3-hydroxy-3-méthyl-hexanoïque (3H3MH) ont été préparés. Le N-hexanoyl glutamine et le N-hexanoyl glutamate ont été utilisés comme template. Nous observons que le MIP synthétisé avec AB comme monomère fonctionnel possède la plus grande capacité d'adsorption pour le N-hexanoyl glutamine, ainsi que pour les précurseurs glutamines des molécules malodorantes. Des résultats préliminaires et très prometteurs ont également été obtenus dans la sueur. La dernière partie de cette thèse concerne des MIPs pour la vectorisation de médicaments. L'acide salicylique (SA) est un médicament efficace utilisé dans le traitement de l’acné. Des MIPs organiques et sol-gel contre SA ont été synthétisés. Les MIPs sol-gel ont une plus grande capacité d’adsorption, 180 μmol.g-1, que les MIPs organiques et ils lient le SA sept fois plus que le NIP. Les tests de relargage du SA ont été effectués dans plusieurs milieux, avec la plus grande efficacité dans l’eau pure. En conclusion, les applications de MIPs en cosmétologie et en vectorisation de médicaments ont étés étudiés. Nos résultats montrent que les MIPs sol-gel sont les plus appropriés pour ce type de travail. / Molecularly imprinted polymers (MIPs) are tailor-made synthetic receptors possessing specific cavities for a given target molecule. They are produced by introducing, into the polymer precursors, guest molecules that act as templates at the molecular level. Interacting and cross-linking monomers are then copolymerized to form a cast-like shell. After removal of the template, cavities complementary to the template in size, shape and position of functional groups are revealed in the polymer, which can now specifically bind the template. Thanks to these specific molecular recognition properties, MIPs have found applications in areas like bio sensors, solid phase extraction, affinity chromatography, catalysis, and drug delivery. Although the MIP concept originated from imprinted silica in the 1930s, imprinted sol-gel materials received little attention afterwards due to the introduction of the more versatile organic polymers as imprinting matrix. However, compared to organic polymers, sol-gels possess higher thermal stability, better water compatibility and larger inner surface area. There have been many applications to biomolecules in aqueous conditions with sol-gel imprinting materials. In this thesis, we have developed organic and silica sol-gel MIPs for applications in cosmetics and drug delivery. MIPs able to adsorb the dandruff-inducing molecule oleic acid (OA) were produced via both the organic and inorganic routes. In the organic MIPs synthesis, different positively charged monomers were used, one of which, acryloyl aminobenzamidine, was specifically synthesized. Although some binding of oleic acid was obtained, specificity and capacity of these polymers were not satisfying. Sol-gel MIPs, on the other hand, exhibited good specific recognition and high binding capacity for OA. A MIP of the composition OA:APTES:TEOS= 1:1.6:1.7 yielded a capacity of 625 μmol.g-1 in artificial sebum. Furthermore, tests were carried out to capture OA on stratum corneum and reconstructed skin (Episkin). Less penetration of OA was observed in the presence of a MIP than with a non-imprinted control polymer. Deodorant materials are another topic of this thesis. MIPs that are able to adsorb certain precursors of odorant molecules, the glutamine conjugates of (E)-3-methyl-2-hexenoic acid (3M2H) and 3-hydroxy-3-methyl-hexanoic acid (3H3MH) were prepared. N-hexanoyl glutamine and N-hexanoyl glutamate were used as templates. After optimization of the MIP composition, we found that MIPs synthesized with acryloyl aminobenzamidine as functional monomer had the highest adsorption capacity for N-hexanoyl glutamine, and also recognised the glutamine targets of 3M2H and 3H3MH. Some preliminary promising binding results were obtained in artificial sweat. The third part of this work concerns a drug delivery MIP. Salicylic acid (SA) is a drug used to treat acne. SA-imprinted polymers were prepared via both organic imprinting and the sol-gel process.Compared to organic MIPs, sol-gel MIPs have a higher capacity, 180 μmol.g-1, and 7 times higher binding than to a non-imprinted control polymer was observed. Release tests were carried out in different aqueous media, the most efficient drug release was observed in pure water. In conclusion, applications of molecularly imprinted polymers for cosmetics and drug delivery have been investigated. Our results demonstrate the great potential of in particular sol-gel MIPs for these purposes.

As Sulfonamidas (SAs) são antibióticos de uso muito comum na medicina veterinária, sendo também aplicadas na medicina humana. Os resíduos dessas substâncias, ou dos seus metabolitos na carne e outros alimentos, podem causar efeitos adversos para a saúde dos consumidores como, por exemplo, resistências a antibióticos e alergias. Este trabalho apresenta o desenvolvimento e aplicação de métodos modernos de preparo de amostra para determinação de multiresíduo de sulfonamidas em alimentos por cromatografia líquida acoplada a espectrometria de massas e ultravioleta visível. Dentre os métodos de preparo de amostra, aplicou-se o método de extração QuEChERS (Quicky, Easy, Cheap. Effective, Rugged, Safe) modificado, em combinação com a cromatografia liquida acoplada a espectrometria de massas, para a análise de dez sulfonamidas em amostras de músculo de frango e bovino. No segundo estudo, seguindo a tendência de miniaturização, sintetizou-se um polímero molecularmente impresso (Sulfadimetoxina-MIP) para uso como sorbente em dispositivos de Microextração com Sorbentes Empacotado (MEPS). O método, denominado SDM-MIP-MEPS, foi otimizado e aplicado em amostras de músculo de frango usando a cromatografia liquida com detecção por ultravioleta-visivel. Embora o uso do polímero molecularmente impresso (MIP) como sorbente seletivo para o MEPS já tenha sido reportada em dois trabalhos, pela primeira vez é descrito a aplicação de um MIP impresso com sulfdimetoxina (SDM), usando MEPS para extração de sulfonamidas em músculo de frango. Portanto, a novidade neste caso, é o uso da nova técnica extração miniaturizada (MEPS) com o polímero sintetizado sulfadimetoxina-MIP como sorbente de empacotamento. As metodologias foram validadas com sucesso de acordo com as diretrizes 657/2002/EU. / Sulfonamides are widely used in veterinary and human medicine. Residues of these compounds, or their metabolites in animal meats and other foods, are toxic and can cause side effects in human\'s health, such as resistance to antibiotics and allergic reactions. This study describes the development and application of a modern sample preparation approach for sulfonamides multiresidue determination in food by chromatographic methods coupled to mass spectrometry and ultraviolet-visible spectroscopy. Among those sample preparation methods, the modified QuEChERS extraction in combination with liquid chromatography in tandem with mass spectrometric detection was applied to the analysis of residues of 10 sulfonamides in chiken and cattle muscle. In the second study, following the miniaturization trends, it was synthesized a molecularly imprinted polymer (Sulfadimethoxine-MIP), for application as sorbent in Microextraction by Packed Sorbents (MEPS). The extraction method was optimized and successfully applied to chicken muscle samples in combination with highperformance liquid chromatography by ultraviolet-visible detection. Although the use of MIPs as selective packing materials for MEPS has already been reported in two papers, is first time that application of a MIP imprinted with Sulfadimethoxine is evaluated for the extraction of sulfonamides in chicken muscle. Therefore the novelty of the present work is the use of this new miniaturization extraction technique with synthesized sulfadimethoxine-MIP polymer as packing sorbent. The methods were successfully validated according to the 2002/657/EC guidelines.