Copper determination in ethanol fuel samples by anodic stripping voltammetry at a gold microelectrode

Autor(es)

Takeuchi, Regina M. ^[1] ; Santos, Andre L. ^[1] ; Medeiros, Maria J. ^[2] ; Stradiotto, Nelson R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista UNESP, BR-14801970 Araraquara, SP - Brazil

^[2] Univ Minho, Ctr Quim, P-4704553 Braga - Portugal

• Tipo de documento: Artigo Científico
• Fonte: Microchimica Acta; v. 164, n. 1-2, p. 101-106, JAN 2009.
• Citações Web of Science: 32

Resumo

A linear sweep anodic stripping voltammetric method was developed for copper determination in commercial ethanol fuel samples by using a gold microelectrode. Under the optimized conditions, a linear range from 0.05 to 1.0 mu M was obtained, with detection limit of 22 nM. The method was employed to determine copper ions in six commercial ethanol fuel samples and the results were compared with those obtained by FAAS. This study showed that for most samples both methods produced concordant results. However, for two samples, copper is distributed in its labile and complexed forms leading to copper contents contrasting with those obtained by flame atomic absorption spectroscopy (FAAS). It was observed that acidification of the samples is a very efficient way to recover copper from its complexed forms. After acidification, the copper contents obtained were concordant with those obtained by FAAS. Thus, the method can be employed to the reliable copper determination in commercial ethanol fuel samples. Moreover, this is the first work providing some insights about copper speciation in commercial ethanol fuel samples. (AU)

• Processo FAPESP: 03/09334-7 - Desenvolvimento de sensores eletroquimicos baseados em silicas organofuncionalizadas para a determinacao de metais pesados em alcool combustivel.
• Beneficiário: Regina Massako Takeuchi
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 03/05567-7 - Estudo eletroquímico de dicloroacetamidas com atividade antiamebíaca
• Beneficiário: André Luiz dos Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado