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Desenvolvimento de eletrodos ion-seletivos : aplicação em sistema de detecção em FIA e estrategias para a melhoria do limite de detecção / Development of ion-selective electrodes: application in detection system of FIA and strategies for the improvement of detection limitTorres, Karin Yanet Chumbimuni 27 September 2005 (has links)
Orientador: Lauro Tatsuo Kubota / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-05T11:12:36Z (GMT). No. of bitstreams: 1
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Previous issue date: 2005 / Resumo: O presente trabalho de doutorado descreve o desenvolvimento de eletrodos íon-seletivos para cálcio, potássio, sódio e cloreto em sistema de injeção em fluxo e sua aplicação para determinação simultânea em sucos de frutas, bem como o desenvolvimento de eletrodos íon-seletivos de contato sólido com baixo limite de detecção. A construção dos eletrodos íon-seletivos para os íons cálcio, potássio, sódio e cloreto foi primeiramente realizado em estado estacionário para logo ser incorporada em sistema de injeção em fluxo. A otimização de parâmetros comuns, tais como: pH, tampão, volume de injeção, vazão, entre outros, possibilitaram a realização da determinação simultânea, utilizando um arranjo de eletrodos em série. O sistema FIA potenciométrico proposto foi satisfatório para determinação simultânea destes íons em amostras de sucos, e os resultados quando comparados com os obtidos pelo método de referência foram estatisticamente iguais num nível de confiança de 95%. Em relação ao desenvolvimento de eletrodos íon-seletivos com baixo limite de detecção, quatro eletrodos diferentes foram desenvolvidos para os íons prata, chumbo, cálcio e iodeto com excelente resposta nernstiana e limite de detecção na faixa nanomolar, que foram 2 nmol L para Ag, 1 nmol L para Pb, 4 nmol L para Ca e 10 nmol L para I. Isto foi conseguido pelo uso do polímero condutor, poli(3-octiltiofeno) como interface entre o contato sólido e a membrana polimérica, o copolímero metilmetacrilato-decilmetacrilato. Os eletrodos desenvolvidos mostraram resposta rápida e boa repetibilidade, sendo promissores para sua utilização em determinações em nível de traço / Abstract: The present work describes the development of ion-selective electrodes for calcium, potassium, sodium and chloride to be employed in flow injection analyses and its application for the simultaneous determination in samples, as well as, the development of solid contact ionselective electrodes with detection limit in the nanomolar range. The preparation of ion-selective electrodes for calcium, potassium, sodium and chloride was performed optimizing them in steady-state and then incorporated in simultaneous low injection analyses. The optimization of common parameters, such as: pH, buffer, injection volume, flow, etc., was performed looking for the simultaneous determination, using an array of electrodes in series. The proposed potentiometric FIA system was satisfactory for simultaneous determination of these ions in juice samples, and the results, when compared to the reference method, were statistically the same in the 95% of confidence level. In relation to the development of solid contact ion-selective electrodes with low detection limit, four different electrodes were developed for silver, lead, calcium and iodide, with excellent nernstian response and detection limit in the nanomolar range. The obtained detection limits were 2 nmol L for Ag, 1 nmol L for Pb, 4 nmol L for Ca e 10 nmol L for I. It was possible by using the conducting polymer, poly(3-octylthiophene) as an interface between the solid contact and polymeric membrane, methyl metacrylate decyl metacrylate copolymer. The electrodes presented short response time and good repetibility, being potentially useful for determination in trace levels / Doutorado / Quimica Analitica / Doutor em Ciências
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Mercaptobenzothiazole-on-Gold Biosensor Systems for Organophosphate and Carbamate Pesticide Compounds.Somerse, Vernon Sydwill. January 2007 (has links)
<p>This study firstly reports the development, characterisation, and application of thick-film acetylcholinesterase (AChE) biosensors based on a gold electrode modified with a mercaptobenzothiazole (MBT) self-assembled monolayer and either poly(omethoxyaniline) (POMA) or poly(2,5-dimethoxyaniline) (PDMA) in the presence of polystyrene(4-sulphonic acid) (PSSA). The Au/MBT/POMA-PSSA/AChE and Au/MBT/PDMA-PSSA/AChE biosensors were then applied to successfully detect standard organophosphorous and carbamate pesticides in a 0.1 M phosphate buffer, 0.1 M KCl (pH 7.2) solution. Secondly, it reports the construction of the Au/MBT/PANI/AChE/PVAc thick-film biosensor for the determination of certain organophosphate and carbamate pesticide solutions in selected aqueous organic solvent solutions.</p>
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Mercaptobenzothiazole-on-Gold Biosensor Systems for Organophosphate and Carbamate Pesticide Compounds.Somerse, Vernon Sydwill. January 2007 (has links)
<p>This study firstly reports the development, characterisation, and application of thick-film acetylcholinesterase (AChE) biosensors based on a gold electrode modified with a mercaptobenzothiazole (MBT) self-assembled monolayer and either poly(omethoxyaniline) (POMA) or poly(2,5-dimethoxyaniline) (PDMA) in the presence of polystyrene(4-sulphonic acid) (PSSA). The Au/MBT/POMA-PSSA/AChE and Au/MBT/PDMA-PSSA/AChE biosensors were then applied to successfully detect standard organophosphorous and carbamate pesticides in a 0.1 M phosphate buffer, 0.1 M KCl (pH 7.2) solution. Secondly, it reports the construction of the Au/MBT/PANI/AChE/PVAc thick-film biosensor for the determination of certain organophosphate and carbamate pesticide solutions in selected aqueous organic solvent solutions.</p>
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Mercaptobenzothiazole-on-Gold Biosensor Systems for Organophosphate and Carbamate Pesticide CompoundsSomerse, Vernon Sydwill January 2007 (has links)
Philosophiae Doctor - PhD / This study firstly reports the development, characterisation, and application of thick-film acetylcholinesterase (AChE) biosensors based on a gold electrode modified with a mercaptobenzothiazole (MBT) self-assembled monolayer and either poly(omethoxyaniline) (POMA) or poly(2,5-dimethoxyaniline) (PDMA) in the presence of polystyrene(4-sulphonic acid) (PSSA). The Au/MBT/POMA-PSSA/AChE and Au/MBT/PDMA-PSSA/AChE biosensors were then applied to successfully detect standard organophosphorous and carbamate pesticides in a 0.1 M phosphate buffer, 0.1 M KCl (pH 7.2) solution. Secondly, it reports the construction of the Au/MBT/PANI/AChE/PVAc thick-film biosensor for the determination of certain organophosphate and carbamate pesticide solutions in selected aqueous organic solvent solutions. / South Africa
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