Estudo do comportamento eletroquímico de alguns agentes antifúngicos utilizando polarografia de pulso diferencial e voltametria de redissolução catódica
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Data
1999-10-13
Autores
Pereira, Francisco Claudece [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O comportamento voltamétrico de dois agentes antifúngicos denominados de Clotrimazol e Miconazol foi investigado em meio hidrometanólico sobre eletrodo de mercúrio. Clotrimazol e miconazol são reduzidos em potencial bastante negativo em solução tampão B-R pH > 6 através da transferência reversível de 1 elétron à ligação C-Cl, cujo mecanismo de redução foi investigado através de PPD e VC. Para a determinação destes compostos em meio aquoso, recomenda-se a adição de 0,001% de Triton X-100 através da qual obteve-se uma curva de calibração linear entre 5x10- 6 a 2,8x10- 4 mol.L- 1 para clotrimazol em solução tampão fosfato pH 6,9 e para miconazol 192,0 a 718,5 ng.mL- 1 em solução tampão B-R pH 8,0 Um novo método para determinação indireta de clotrimazol através da técnica polarográfica de pulso diferencial foi investigado através da reação de derivatização do fármaco com o corante reativo Procion Red HE-3B (RR 120). O produto da reação entre a função clorotriazina do corante e clotrimazol...
Clotrimazole is reduced at mercury electrode above pH 6 involving a reversible one-electron process. The electrodic process presents a large contribution of the adsorption effects. For the differential pulse polarographic determination is recommended the addition of Triton X-100, which promotes a linear calibration curve from 5x10- 6 mol.L- 1 to 2,8x10- 4mol. L- 1. In addition, clotrimazole can be determined by cathodic stripping voltammetry at 5ng.mL- 1 level when pre-accumulated for 1 min at an accumulation potential of -0,2V. The proposed method have shown a linear calibration curve from 103 to 345ng.mL- 1 and can be applied successfully for the determination of the clotrimazole in commercial formulations. Interaction of the clotrimazole with reactive dye Procion Red HE-3B (RR 120) was investigated in aqueous solution by differential pulse polarography. The clotrimazole derivatized with the reactive dye in B-R buffer (pH 2) yielded a sensitive polarographic response at -0,38V (vs Ag/AgCl). Analytical parameters such as pH, buffer compositions, temperature, reaction time and concentration of dye have been optimised. Linear calibration curves for clotrimazole have been construted from 10-34 μg.mL- 1 using 1x10- 4 mol.L- 1 of the dye at room temperature. The method has been applied to the determination of clotrimazole in pharmaceutical preparations...(Complete abstract, click electronic access below)
Clotrimazole is reduced at mercury electrode above pH 6 involving a reversible one-electron process. The electrodic process presents a large contribution of the adsorption effects. For the differential pulse polarographic determination is recommended the addition of Triton X-100, which promotes a linear calibration curve from 5x10- 6 mol.L- 1 to 2,8x10- 4mol. L- 1. In addition, clotrimazole can be determined by cathodic stripping voltammetry at 5ng.mL- 1 level when pre-accumulated for 1 min at an accumulation potential of -0,2V. The proposed method have shown a linear calibration curve from 103 to 345ng.mL- 1 and can be applied successfully for the determination of the clotrimazole in commercial formulations. Interaction of the clotrimazole with reactive dye Procion Red HE-3B (RR 120) was investigated in aqueous solution by differential pulse polarography. The clotrimazole derivatized with the reactive dye in B-R buffer (pH 2) yielded a sensitive polarographic response at -0,38V (vs Ag/AgCl). Analytical parameters such as pH, buffer compositions, temperature, reaction time and concentration of dye have been optimised. Linear calibration curves for clotrimazole have been construted from 10-34 μg.mL- 1 using 1x10- 4 mol.L- 1 of the dye at room temperature. The method has been applied to the determination of clotrimazole in pharmaceutical preparations...(Complete abstract, click electronic access below)
Descrição
Palavras-chave
Quimica analitica, Polarografia, Polarographic
Como citar
PEREIRA, Francisco Claudece. Estudo do comportamento eletroquímico de alguns agentes antifúngicos utilizando polarografia de pulso diferencial e voltametria de redissolução catódica. 1999. 189 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Química, 1999.