N-propylpyridinium chloride silsesquioxane polymer film on graphite: electrochemical study of a hexacyanoferrate (II) ion immobilized electrode for oxidation of ascorbic acid

• Autor(a) principal: Alfaya,Rení V. S.
• Data de Publicação: 2000
• Outros Autores: Gushikem,Yoshitaka, Alfaya,Antonio A. S.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532000000300014
• topic: N-propylpyridinium chloride silsesquioxane polymer-coated graphite electrode; hexacyanoferrate(II) ion; electroacatalytic oxidation; amperometric determination; ascorbic acid

A well polished graphite surface was coated with a thin film of N-propylpyridinium chloride silsesquioxane polymer. On to the strongly graphite-adhered polymer film the electroactive species [Fe(CN)6]4- was adsorbed by means of an ion exchange reaction. The resulting electrode (graph/SiPy+)4[Fe(CN)6 ]4- (graph = graphite and SiPy+ represents the N-propilpyridinium silsesquioxane polymer) was chemically very stable and was used to electrocatalytically oxidize ascorbic acid in solution (pH between 4.5-6.5) in 0.1 mol dm-3 KCl. The electrode was used to determine vitamin C in tablets and in processed orange juices. The results were in accord with those obtained by using the standard 2,6-dichlorophenolindophenol titration method.