Data/hora: 23/06/2024 10:21:59

Biblioteca(s): | Embrapa Instrumentação.
Data corrente: | 09/03/2005
Data da última atualização: | 25/11/2009
Autoria: | SIMÕES, F. R.; MATTOSO, L. H. C.; VAZ, C. M. P.
Título: | Modified carbon paste-polyaniline electrodes for the electrochemical determination of the herbicide 2,4-D.
Ano de publicação: | 2004
Fonte/Imprenta: | Sensor letters, [S. l.], v. 2, n. 3-4, p. 221-225, 2004.
Idioma: | Inglês
Conteúdo: | Redox processes of pesticides have been used to establish electroanalytical procedures to determine these compounds in natural samples. For the herbicide 2,4 dichlorophenoxyacetic acid (2,4-D) it has been shown that no redox process take place in the most common electrode material (carbon, platinum, mercury) and electroanalytical conditions used. Modified carbon paste electrodes has been shown to be an alternative for the electrochemical determination of the herbicide 2,4-D. We investigate in this paper three modified carbon paste-polyaniline electrodes, using in-situ electropolymerization of aniline on the carbon paste surface (CPE1), mixing polyaniline powder with the carbon paste material (CPE2) and in-situ chemical polymerization of aniline on graphite powder (CPE3). The affinity of the 2,4-D with the polyaniline was investigated with UV-visible spectrophotometry and the electrochemical response of the three modified carbon paste-polyaniline electrodes by cyclic voltammetry. the UV-vis. results showed that about 60% of the herbicide sorbed on the polyaniline particles after 24 hours of contact. Typical cyclic voltammograms of the polyaniline were affected by the presence of the herbicide on polyaniline, increasing both anodic and cathodic currents at approximately 200 mV and 0 mV for the CPE2 and CPE3 electrodes. The best response was obtained with the CPE3 electrode.
Palavras-Chave: | Determinação Eletroquimica.
Thesagro: | Carbono; Herbicida.
Categoria do assunto: | --
Registro original: | Embrapa Instrumentação (CNPDIA)
Exemplares: | CNPDIA - (8708-1) - UPC - SP - -- - PROCI-04.00157 -  - 2004.00157 - DIS