Spelling suggestions: "subject:"anvis"" "subject:"anivis""
1 |
Charakteristika vybraných preparátů huminových kyselin pomocí nukleární magnetické resonanceBoháčová, Lucie January 2013 (has links)
No description available.
|
2 |
Part I: The Synthesis and Characterization of Scorpionate Ligands for Lanthanide Complexation for Potential PARACEST Applications. Part II: The Synthesis and the Characterization of New and Old Organic DyesNicholls-Allison, Emma 21 April 2015 (has links)
Reported in Chapter 2 of this thesis is the reliable and tolerant synthesis of a small library
of pyrazole and triazole heterocycles. This synthesis was achieved in two steps in good
yields from the reaction of acetophenone and benzamide derivatives with dimethyl
formamide-dimethyl acetal followed by a cyclization with hydrazine. Also reported is the
synthesis and characterization of their corresponding scorpionate ligands. Preliminary co
ordination chemistry was done with a variety of lanthanide metals and was studied by
standard spectroscopic methods as well as variable temperature 1H NMR, which revealed
that Curie-Weiss behaviour was followed for these complexes in solution. An X-ray
crystal structure of a nine co-ordinate ytterbium metal centre with eight nitrogen atom (four
pyrazole, four pyridine) donors and one chloride atom was obtained, which may have been a product of decomposition during crystal growth. The bond lengths of this structure were compared with other lanthanide complexes of similar structural motifs. This comparison supported the theory of decomposition as the pyridine nitrogen atom-ytterbium bond lengths were longer than the average ytterbium-nitrogen atom bond length.
Reported in Chapter 4 of this thesis is the synthesis and partial characterization of a new
organic dye named perinaphthindigo. Perinaphthindigo was synthesized with adapted
iv Baeyer-Drewson reaction conditions for the synthesis of indigo which involved the
treatment of 1,8-nitronaphthaldehyde with acetone under basic conditions, and was found
to be an intense green colour in solution. Perinaphthindigo was produced in poor yields,
so efforts were undertaken to improve the yields through an alternative two-step synthesis, first between 1,8-nitronaphthaldehyde and nitromethane in a Henry reaction followed by oxidative coupling. The synthesis of perinaphindigo was adapted so as to structurally modify the final compound, either through incorporation of solubilizing tert-butyl groups or bromine atoms for future cross-coupling chemistry. The brominated derivatives of perinaphthindigo were also synthesized in low yields so cross-coupling conditions were scanned on model precursor compounds. The brominated perinaphthindigo compounds were found to have a bathochromically shifted absorbance maximum from the parent perinaphthindigo. This bathochromic shift was more pronounced in our compounds than in the comparison of indigo and 6.6’-dibromoindigo which indicates our compounds are more sensitive to perturbation by substitution.
Reported in Chapter 5 of this thesis is the study of the acid and base chemistry of
Nindigo, a previously reported compound. The treatment of Nindigo with a series of strong acids led to an interesting “protoisomerization”, or trans to cis isomerization of the central olefin, with ultimate structural determination through X-ray crystallographic methods. This isomerization was studied through absorbance stopped-flow methods which identified a probable pathway of the isomerization through a neutral, cis species. The investigation of neutral Nindigo was undertaken to attempt to identify two peaks which are red-shifted from the π-to-π transition at 586 nm. These two peaks appear at 657 nm and 741 nm and are present in all solvents. The preparative acid chemistry allowed us to assign the first red shifted peak at 657 nm to the cationic species. Aggregation studies showed concentration dependent behaviour of the ratio between the peaks at 586 nm and 657 nm with little effect on the species at 741 nm. In order to probe whether an autoionization process was occurring, variable temperature NMR and UV-Vis experiments were performed which did not provide a definitive answer to the species at 741 nm. / Graduate
|
3 |
Nanomaterials Self-Assembly Driven by Beta-Amyloid PeptidesTanase, Maria Elena 20 May 2005 (has links)
Nanomaterials such as gold nanowires and gold nanoparticles were self-assembled with several peptides derived from betaamyloid peptide. The peptides propensity to form fibrilar structures was exploited. The products obtained by aggregation of the peptides with the nano materials were studied using HPLC, UV-vis spectroscopy, TEM and optical light microscopy.
|
4 |
Eletrodeposição de CuNi em meio de sulfato. uma nova abordagem / electroplating of cuni in sulphate.a new boardingPacheco, Luisa 04 September 2006 (has links)
PACHECO, L.C.M. Eletrodeposição de CuNi em meio de sulfato. Uma nova abordagem . 2006. 94 f. Dissertação (Mestrado em Química Inorgânica) – Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2006 / Submitted by irlana araujo (irlanaaraujo@gmail.com) on 2011-12-29T12:38:16Z
No. of bitstreams: 1
2006_dist_Lui_Pacheco.pdf: 4245121 bytes, checksum: 08675884bda731783aaae834c7bc8f7a (MD5) / Approved for entry into archive by Aline Nascimento(vieiraaline@yahoo.com.br) on 2012-02-14T14:31:44Z (GMT) No. of bitstreams: 1
2006_dist_Lui_Pacheco.pdf: 4245121 bytes, checksum: 08675884bda731783aaae834c7bc8f7a (MD5) / Made available in DSpace on 2012-02-14T14:31:44Z (GMT). No. of bitstreams: 1
2006_dist_Lui_Pacheco.pdf: 4245121 bytes, checksum: 08675884bda731783aaae834c7bc8f7a (MD5)
Previous issue date: 2006-09-04 / The interest for the electroplating of CuNi and its multiple layers is proportionate to the properties of these materials, such as: mechanical resistance to corrosion, mechanical (high tractive force, malleability and ductility) and magnetic properties, beyond its catalytic properties. The voltammetric results suggest that CuNi is electroplated, forming a solid solution. By cyclic voltammetry, the influence of different electrolytic bath in the electroplating of CuNi was investigated, where if it observed the formation of more noble alloys in sulphate baths and tartarate and less noble alloys in citrate and citrate/tartarate medium. Hydrodynamic experiments had been carried through, where it was verified for CuNi in sulphate and tartarate a transport of diffusional mass; for CuNi in citrate and citrate/tartarate was not observed the formation of diffusional plateau, suggesting a transport of mass by charge transference. By dispersive energy of rays-X, the atomic percentage of the constituent of the alloy was determined, where CuNi alloy in sulphate bath and tartarate present a percentage of nickel about 20% and in citrate and citrate/tartarate medium, the percentage of nickel falls espectively for 2% and 4%. By spectrometry of absorption of UV-Vis it was calculated the _ values for individual metals and CuNi, being found low values, indicating that as much the individual metals as the alloy in the different electrolytic transitions d-d type. It was made a comparative study between the electrochemical techniques (Linear Sweep Voltammetry, Chronoamperometry) and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), for copper determination. The copper taxes determined for both methods are near, presenting small variations, where the gotten errors are distributed in a random way presenting an average value of 2,56%. The carried through statistical tests had shown that the gotten results are in a reliable band of 95%. Based in these results it is possible to affirm that the used electrochemical techniques are efficient in the copper determination, making possible, thus, the validation of these for ICP-OES. / O interesse pela eletrodeposição de CuNi e suas múltiplas camadas é principalmente devido às propriedades destes materiais, tais como: resistência à corrosão, propriedades mecânicas (alta força de tração, maleabilidade e ductilidade) e magnéticas, além de suas propriedades catalíticas. Os resultados voltamétricos deste trabalho sugerem que a liga de CuNi é eletrodepositada formando uma solução sólida. Por voltametria cíclica, foi investigada a influência de diferentes banhos complexantes na eletrodeposição de CuNi, onde se observou a formação de ligas mais nobres em banhos de sulfato e tartarato e ligas menos nobres em meio de citrato e citrato/tartarato. Foram realizados experimentos hidrodinâmicos, onde severificou que CuNi em meio de sulfato e tartarato apresentam transporte de massa difusional. Para CuNi em meio de citrato e citrato/tartarato, não foi observado a formação de patamares difusionais, onde se sugere um transporte de massa por transferência de carga ou misto. Pelos resultados obtidos observou-se que o meio complexante influência na nobreza e no tipo de transporte de massa da liga formada. Por Energia Dispersiva de Raios-X, foi determinado o percentual atômico dos constituintes da liga, onde as ligas CuNi em banho de sulfato e tartarato apresentam um percentual de níquel em tono de 20% e em meio de citrato e citrato/tartarato, o percentual de níquel cai para 2% e 4%, respectivamente. Por espectrometria na região de absorção do UV-Vis, foram feitos curvas de calibração e calculado _ para os metais individuais e para CuNi, sendo encontrado baixos valores, indicando que tanto os metais individuais como a liga nos diferentes meios complexantes apresentam transições do tipo d-d. Foi feito um estudo comparativo entre as técnicas eletroquímicas (VLDA, Cronoamperometria) e ICP-OES para determinação de cobre. Os teores de cobre determinados para ambos os métodos encontram-se bem próximos, mostrando pequenas variações, onde os erros obtidos estão distribuídos aleatoriamente, apresentando um valor médio de 2,56%. Os testes estatísticos realizados mostraram que os resultados obtidos estão numa faixa de confiança de 95%. Baseado nestes resultados é possível afirmar que as técnicas eletroquímicas utilizadas são eficientes na determinação de cobre, possibilitando, assim, a validação destas por ICP-OES.
|
5 |
Towards new approaches for the generation of phosphorus based radical : synthetic and mechanistic investigations / Nouvelles approches pour la génération de radicaux à base de phosphore : études synthétiques et mécanistiquesFausti, Giovanni 24 July 2017 (has links)
Cette thèse rapporte trois modes d'activation complémentaires pour la génération de radicaux à base de phosphore, qui ont été utilisés pour la synthèse de composés organophosphorés.Tout d’abord, nous avons décrit une génération photocatalytique de radicaux phosphinoyle en utilisant le sel d'acridinium, le perchlorate de 9-mésityl-10-méthylacridinium connu sous le nom de catalyseur de Fukuzumi, en tant que photocatalyseur, et triflate de diphényliodonium comme photo-oxydant externe. Ce système purement organique nous a permis d'obtenir la première hydrophosphinylation sans métal des alcènes. Plusieurs enquêtes mécaniques, telles que la résonance paramagnétique électronique (EPR), la photolyse laser, la fluorescence et les quantum yields measurements ont été utilisées pour comprendre les facteurs qui régissent cette photoréaction.Dans le chapitre suivant, la formation de complexes Electron-Donor-Acceptor (EDA) entre les oxydes de phosphine secondaires et l'ion diphényliodonium a été utilisée pour générer un radical phosphinoyle sous irradiation bleue. Des études expérimentales et théoriques combinées ont été utilisées pour élucider la formation de complexes d'EDA. Cette stratégie a ensuite été utilisée pour décrire l'hydrophosphinylation des alcènes.Le dernier chapitre rapporte une méthode légère sans métal pour la synthèse d'oxindoles phosphorylés, qui sont des composés pharmaceutiques potentiellement actifs. La portée et les limites de cette approche ont été discutées avec des enquêtes mécanistiques préliminaires. / This Thesis reports three complimentary modes of activation for the generation of phosphorus based radicals, which have been employed for the synthesis of organophosphorus compounds.We have first described a photocatalytic generation phosphinoyl radicals by using the acridinium salt, 9-mesityl-10-methylacridinium perchlorate known as Fukuzumi’ catalyst, as a photocatalyst and diphenyliodonium triflate as an external photooxidant. This purely organic system allowed us to achieve the first metal–free hydrophosphinylation of alkenes. Several mechanistic investigations, such as Electron Paramagnetic Resonance (EPR), Laser Flash Photolysis, fluorescence quenching and quantum yields measurements have been employed to understand factors governing this photoreaction.In the subsequent chapter, the formation of Electron–Donor–Acceptor complexes (EDA) between secondary phosphine oxides and the diphenyliodonium ion has been used to generate phosphinoyl radical under blue irradiation. A combined experimental and theoretical investigations have been used to elucidate the formation of EDA complexes. This strategy has then been employed to describe hydrophosphinylation of alkenes.The last chapter reports a metal–free visible light mild method for the synthesis of phosphorylated oxindoles, which are potentially active pharmaceutical compounds. Scope and limitations of this approach have been discussed along with preliminary mechanistic investigations.
|
6 |
Infrared and Uv-Vis Spectroscopic Studies of Catalytic Reaction of Enzymes and Immobilization Enzyme on Porous PolymersChen, Xi 27 May 2015 (has links)
No description available.
|
7 |
Síntese e caracterização de derivados naftalimídicos e sua copolimerização com estireno para geração de materiais poliméricos fluorescentes / Synthesis and characterization of naphthalimides derivatives and their copolymerization with styrene to generate fluorescent polymeric materialsSchimidt, Marcos Felipe Russo Assumpção 15 February 2019 (has links)
O fascínio e a curiosidade da humanidade pela luz incentivaram a compreensão dos fenômenos que envolvem a interação matéria-energia, levando a um avanço tecnológico jamais visto antes. Com essa compreensão, atualmente é possível criar materiais com inúmeras finalidades; como na extensa área de micro e optoeletrônica; como na confecção de OLEDs e OPVs; no desenvolvimento de revestimentos inteligentes; marcadores biológicos; materiais para drug delivery; entre muitas outras aplicações. Seguindo essa perspectiva, a classe dos corantes rilênicos conhecida por naftalimidas possuem propriedades únicas que permitem a confecção dos mais diversos materiais. Desta maneira, o presente estudo sintetizou dois monômeros naftálicos inéditos derivados da 1,8-naftalimida e da 1,4,5,8-naftalenodiimida, os monômeros NI-AL e NDI-ALp. Além disso, também foram sintetizados dois copolímeros compostos por estireno-co-NI-AL e estireno-co-NDI-ALp. Para cada copolímero houve a variação da proporção estireno/comonômero, gerando, ao todo, dez copolímeros (seis de estireno-co-NI-AL e quatro de estireno-co-NDI-ALp). Os copolímeros foram analisados através de técnicas espectrométricas (1H RMN, FTIR, UV-Vis, Fluorescência, Reflectância) e cromatográficas (GPC). Os resultados indicaram que o copolímero de estireno-co-NI-AL sofre agregação devido às interações π-π, mas não há transferência de cargas entre os comonômeros. Já o copolímero estireno-co-NDI-ALp forma uma complexação no estado fundamental, deslocando a fluorescência da NDI-ALp para a região do verde e causando o surgimento de uma banda a 450 nm no espectro de UV-Vis. / The fascination and curiosity of humanity for light has stimulated the understanding of the interaction between energy and matter, leading to a technological advance never seen before. It is now possible to create materials with numerous purposes such as the extensive area of micro and optoelectronics, the manufacturing of OLEDs and OPVs, the development of intelligent coatings, biological markers, materials for drug delivery, among many others applications. Following this perspective, a class of rylene dyes known as naphthalimides have unique properties that allow the synthesis of numerous materials. In this study, two novel naphthalene allyl monomers derived from 1,8-naphthalimide and 1,4,5,8-naphthalenediimide have been synthesized, the monomers NI-AL and NDI-ALp. In addition, copolymers of styrene-co-NI-AL and styrene-co-NDI-ALp presenting different compositions were also synthesized. For each copolymer, the styrene: comonomer ratio varied, generating altogether tem copolymers (six of styrene-co-NI-AL and four of styrene-co-NDI-ALp). The copolymers were analyzed by spectrometric (1H NMR, FTIR, UV-Vis, Fluorescence) and chromatographic (GPC) techniques. The results indicated that the styrene-co-NIAL copolymer undergoes aggregation due to the π-π interactions, but there is no charge transfer between the comonomers. However, the styrene-co-NDI-ALp copolymer forms a complexation in the ground state, displacing the NDI-ALp fluorescence to the green region and causing the appearance of a band at 450 nm in the UV-Vis spectrum attributed to charge transfer complexes.
|
8 |
Caracterização de Ferroporfirinas através das técnicas de ressonância paramagnética eletrônica (EPR) e absorção eletrônica na região do ultravioleta-visível (UV-Vis) / Ironporphyrins characterization studies by paramagnetic resonance and UV-vis techniquesVidoto, Ednalva Aparecida 24 November 1999 (has links)
As ferroporfirinas sintéticas são sistemas complexos que vêm sendo amplamente estudadas. A dificuldade em obter informações estruturais, reações químicas e ligantes do íon central vêm estimulando o estudo pormenorizado desses sistemas. Nestes trabalho é apresentada a caracterização da série de FeP fluorosubstituídas, que compreende as mono-, di-, tri e tetra- fluorofenilporfirina, denominadas FeTF5PP, FeTF10PP, FeTF15PP e FeTF20PP, respectivamente. Essas FeP são estudadas em função dos solventes diclorometano (DCM), metanol (MeOH) e das várias misturas em volume desses dois. As técnicas espectroscópicas de Absorção Eletrônica na região do Ultravioleta ao Visível (UV-Vis) e Ressonância Paramagnética Eletrônica (EPR) são as duas ferramentas de estudos escolhidas para caracterizar esses sistemas. Partindo-se de uma solução de FeP dissolvida em DCM, foram adicionadas alíquotas de Me0H até completar-se 50% em volume desses dois solventes. Através dessa titulação, observamos a formação de diferentes espécies como conseqüência da coordenação do Me0H à FeP. Notamos também, as modificações estruturais reveladas principalmente pelo EPR, ocasionadas pelos diferentes números de substituintes fluorofenis. Essa técnica espectroscópica revelou ainda a existência de interações que não foram anteriormente observadas. Para a FeTFloPP foi verificada a interação super hiperfina entre o Fe e o ligante CF além da interação super hiperfina entre o Fe e os nitrogênios do anel porfirínico. Para a FeTF20PP foi verificada apenas a interação super hipeOna entre o Fe e o ligante Cl-. As demais FeP não apresentaram essas interações / Synthetic iron porphyrins are complex systems that have been largely studied. Difficulties to obtain structural information, chemical reactions and ligands of the central ions have been a subject to investigate details of these systems. In this work, a systematic characterization of one series of fluorophenyl iron porphyrins is presented. Mono-, di-, tri- and tetrafluorophenyl substituents called FeTF5PP, FeTF10PP, FeTF15PP, and FeTF20PP, respectively, are included in this series. Iron porphyrins were studied as a function of dichloromethane, methanol solvents and several of their mixture in volume. These systems were characterized by Ultraviolet- Visible and Electron Paramagnetic Resonance Spectroscopes. From iron porphyrin solutions, dissolved in dichloromethane, aliquots of methanol were added up to 50% in volume of these two solvents. With this titration, we found different species because of the methanol coordination to the iron porphyrins. We also observed the structures modification revealed by the EPR spectroscopy, as a function of different numbers of fluorophenyl substituents. The EPR spectroscopy also revealed the existence of the super hyperfine interactions not observed before. It was found for FeTFloPP between the central ion and the axial ligand chlorine Cl - ion, besides the hyperfine interaction between iron and the nitrogen of the pyrrole ring. For FeTF20PP only the super hyperfine interaction, Fe-C1 was found. These interactions were not observed for the other iron porphyrins
|
9 |
Propriedades ópticas de absorção e emissão fluorescente do ácido orto-aminobenzóico e seus derivados em meio solvente / Optical properties of ortho-aminobenzoic acid and derivatives: absorption and fluorescence emission in solvent mediumTakara, Marcelo 19 December 2006 (has links)
Nesta tese, apresentamos estudos experimentais e teóricos realizados com o Ácido orto-Aminobenzóico (o-Abz) e seus derivados 2-amino-benzamida (o-Abz-NH2), 2-amino-metil-benzamida (o-Abz-NH(CH3)) e 2-amino -dimetilbenzamida (o-Abz-N(CH3)2). Foram feitas medidas de absorção óptica, fluorescência estática e resolvida no tempo e anisotropia de fluorescência em solventes com diferentes graus de polaridade e diferentes capacidades de doar e aceitar prótons. Os resultados experimentais foram comparados aos resultados de simulações computacionais que simularam o sistema solventesoluto. Restrições impostas pelas limitações computacionais impedem cálculos totalmente quânticos via métodos ab-initio, porém uma metodologia que tem apresentado resultados satisfatórios é o método híbrido que envolve a mecânica quântica associada à mecânica molecular (QM/MM). No presente trabalho, foram combinados cálculos quânticos ab-initio e semi-empíricos na otimização de geometrias de moléculas isoladas e no cálculo de energias de transições respectivamente. Foram simulados os sistemas soluto+solvente via Método de Monte Carlo. Os espectros de absorção ótica obtidos via simulação demonstraram boa concordância com os resultados experimentais, identificando-se as bandas como oriundas das transições p-p*. Verificamos que a forma ácida aniônica do o-Abz é responsável pelo deslocamento para o azul, observado em solvente aquoso. A forma aniônica incrementa a eletronegatividade dos átomos de Oxigênio, aumentando a energia das ligações de hidrogênio. Essas ligações mais intensas estabilizam o estado excitado do o- Abz, e isso se reflete no deslocamento para azul. Da simulação, verificou-se também que na forma aniônica há uma inibição das ligações de hidrogênio do tipo doadoras por parte do grupo amina. Os derivados do o-Abz apresentam aumento na capacidade do grupo amina atuar como doador em ligações de hidrogênio e diminuição na soma de todas as ligações de hidrogênio entre soluto-solvente. Os derivados amida e monometilamida mantiveram elevado rendimento quântico e sensibilidade à polaridade ambiente. Por outro lado, o derivado o-Abz-N(CH3)2 mostra sensibilidade à presença de metilas que incrementam as vias de desexcitação não radiativa. / In the present, we report experimental and theoretical studies on orthoaminobenzoic acid (o-Abz) and its derivatives 2 amino-benzamide (o-Abz-NH2), 2 amino-monomethyl-benzamide (o-Abz-NH(CH3)) and 2 amino-dimethyl-benzamide (o-Abz-N(CH3)2. We measured optical absorption, steady state and time-resolved fluorescence and fluorescence anisotropy of the compounds in solvents with different donor/acceptor character. The experimental results were compared with results of computational calculations which simulated solvent-solute systems. Due to the restrictions imposed by the computer limitations, it was not possible to do entire quantum calculations by ab-initio methods. We used then QM/MM methods, which involves quantum calculation with molecular mechanics simulations. In this work, ab-initio and semi-empiric quantum calculations were combined in the single molecule geometry optimization and energy transitions calculus, respectively. The solute-solvent system was simulated by Monte Carlo method. The optical absorption spectra obtained from simulations showed good agreement with experimental results, identifying the bands relative to p-p* transitions. It was observed that the anionic acid form of the o-Abz is responsible for the blue shift when it is in aqueous solution. Anionic form increases the electronegativity of Oxygen atoms, rising the energy of the hidrogen bonds. These strong bonds stabilize the fundamental state of o-Abz, resulting in a blue shift in absorption spetrum. From simulation, it was verified that in the anionic form of o-Abz there is also an inhibition of hidrogen bonds of the donor type by the amine group. Compared to o-Abz alone, the derivatives present an increase in the amine group capacity to act as a hidrogen bond donor. The o-Abz-NH2 and o-Abz- NH(CH3) derivatives preserved the high quantum yield and the sensitivity for the environment polarity, while in the dimethyl amide derivative, the presence of methyl groups increases the deexcitation by non-radiactive pathways.
|
10 |
Desenvolvimento e validação de método para análise do topiramato em amostras de plasma por eletroforese capilar com detecção UV/vis e C4D / Development and validation of method for analysis of topiramate in plasma samples by capillary electrophoresis with UV/vis and C4D detectionIshikawa, Aline Akemi 20 April 2016 (has links)
O topiramato (TPM) é um fármaco antiepiléptico utilizado para o controle de crises epilépticas generalizadas e parciais em adultos e crianças. A determinação da concentração plasmática do TPM em associação com as observações clínicas é de suma importância, uma vez que permite o ajuste individual da dose administrada ao paciente, diminuindo a incidência de reações adversas e melhorando a adesão ao tratamento. No presente trabalho, dois métodos bioanalíticos foram desenvolvidos e validados para análise do TPM em amostras de plasma, por eletroforese capilar utilizando os detectores DAD (detecção indireta) e C4D Lite (detecção condutométrica). A análise eletroforética para ambos os métodos foi realizada em um capilar de sílica fundida de 75 ?m de diâmetro interno e 40 cm de comprimento efetivo. O eletrólito de corrida foi composto por trietanolamina (TEA) 15 mmol L-1 para a detecção condutométrica e TEA 15 mmol L-1, ácido 3,5 dinitrobenzóico (DNB) 5 mmol L-1 e brometo de cetiltrimetilamônio (CTAB) 0,4 mmol L-1 para detecção indireta. As injeções foram feitas no modo hidrodinâmico a 0,8 psi por 5 segundos e a tensão aplicada foi de -20 e 20 kV para detecção indireta e condutométrica, respectivamente. Nestas condições, o TPM migrou em 2,5 min. O preparo das amostras foi realizado por extração líquido-líquido (LLE), usando éter metil-terc-butílico (MTBE) como solvente extrator e utilizando 500 e 200 ?L de plasma para o método com detecção indireta e condutométrica, respectivamente. Os métodos foram validados de acordo com os guias oficiais da Agência Nacional de Vigilância Sanitária e European Medicine Agency e apresentaram linearidade no intervalo de concentração plasmática de 1-30 ?g mL-1 e valores de precisão e exatidão abaixo de 15 %, além de serem seletivos. Assim, ambos os métodos foram aplicados com sucesso em amostras de plasma de pacientes em tratamento com o TPM. Embora os detectores universais geralmente apresentem um maior limite de detecção comparado com detectores seletivos, o método com detecção condutométrica desenvolvido neste trabalho apresentou como vantagem maior sensibilidade em relação método indireto (DAD). Além disso, apresentou também vantagens como simplicidade e baixo custo, mostrando viabilidade na aplicação para análises de rotina. / Topiramate (TPM) is an antiepileptic drug that has been used as an agent for the control of partial and generalized seizures in both adults and children patients. The determination of the plasmatic concentration of TPM in association with clinical observations is of utmost importance for the individual adjustment of the administered dose to the patient. In the present work, two bioanalytical methods have been developed and validated for TPM analysis in plasma samples by capillary electrophoresis using DAD (indirect detection) and C4D Lite detectors (conductometric detection). The electrophoretic analysis for both methods were performed on a fused silica capillary of 75 ?m of internal diameter and 40 cm effective length. The background electrolyte was composed of triethanolamine (TEA) 15 mmol L-1 for conductometric detection and TEA 15 mmol L-1, 3,5 dinitrobenzoic acid (DNB) 5 mmol L-1 and cetyltrimethylammonium bromide (CTAB) 0.4 mmol -1 for indirect detection. The injections were carried out in hydrodynamic mode, at 0.8 psi for 5 seconds, and the voltage applied were -20 e 20 kV for indirect and conductometric detection, respectively. Under these conditions, TPM migrated in 2.5 min. The sample preparation was carried out by liquid liquid extraction (LLE) using methyl tert-butyl ether (MTBE) as solvent, and using 500 and 200 ?L of plasma samples for direct and conductometric detection, respectively. The methods were validated according to the official guides of the Agência Nacional de Vigilância Sanitária and European Medicine Agency, and showed linearity in plasmatic concentration range of 1-30 mg L-1, precision and accuracy values below 15%, beside selectivity. Both methods have been applied successfully to analysis of plasma samples of patients in treatment with TPM. Although universal detectors have a higher quantification limit compared with selective detectors, the method with conductometric detection developed in this work presented greater sensitivity than indirect method (DAD). Furthermore, it also presented advantages such as simplicity and low cost, showing feasibility in applying to routine analysis.
|
Page generated in 0.0299 seconds