Voltametria adsortiva com redissolução catódica e pulso diferencial em misturas de íons metálicos: Uma análise exploratória

• Ano de defesa: 2007
• Autor(a) principal: Silva, Leandra de Oliveira Cruz da
• Orientador(a): Reis, Efraim Lázaro
• Banca de defesa: Fidencio, Paulo Henrique , Neves, Antônio Augusto
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Agroquímica
• Departamento: Agroquímica analítica; Agroquímica inorgânica e Físico-química; Agroquímica orgânica
• País: BR
• Palavras-chave em Português: Voltametria adsortiva; Metais pesados; Calibração multivariada; Análise de componentes principais
• Palavras-chave em Inglês: Adsorptive voltammetry; Heavy metal; Multivariate calibration; Principal component analysis
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA
• Link de acesso: http://locus.ufv.br/handle/123456789/2172

In this paper, the simultaneous determination of cadmium, cobalt, cooper, nickel, lead and zinc ions was proposal using adsorptive cathodic stripping voltammetry with differential pulse method and multivariate calibration, using a Metrohm polarograph, 797 VA Computrace model. The voltammetric method is based on the determination of metallic ions through the use of complexity agent and the phenomenon of adsorption and stripping of the formed complexes. The individual determination of Cd2+, Co2+, Cu2+, Ni2+, Pb2+ and Zn2+ions was realized and a factorial research design was developed using the curves of standard addition of each ion based in the factorial planning 26, using two levels of concentration for each one of the six studied ions, generating 64 standard mixtures. Voltammetric readings of the 64 solutions of the planning were performed and the obtained data had been submitted to chemometrics treatments as Principal Component Analysis (PCA) and Partial Least Squares (PLS) methods. Related to the data treatment, it had been obtained important considerations of the results with the use of the PCA, allowing to characterize the trends of the solutions and interferences among the ions them self. The use of the chemometric method PLS did not produce satisfactories results to the simultaneous determination of cadmium, cobalt, cooper, nickel, lead and zinc ions in synthetic mixtures. Amongst the presented models, it had been concluded that the model in which the data had been smoothed and derivated supplied fewer errors than the model in what the data had only been smoothed. The application of the chemometrics treatments in the available real samples was not possible, for the fact that the samples did not present the concentrations of studied metals within the band of concentration used in the development of this work.