Monitoramento da degradação eletroquímica de fármacos em água usando anodos de diamante dopado com boro empregando espectroscopia UV/Vis e resolução de curva multivariada

• Ano de defesa: 2012
• Autor(a) principal: Paiva, Juliana Cerqueira de
• Orientador(a): Teófilo, Reinaldo Francisco
• Banca de defesa: Silva, Gilmare Antônia da , 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: Diamante dopado com Boro; Degradação eletroquímica; Fármacos; Espectroscopia UV/VIS; Quimiometria
• Palavras-chave em Inglês: Boron-doped diamond; Electrochemical degradation; Pharmaceuticals; Spectroscopy UV/VIS; Chemometric
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA
• Link de acesso: http://locus.ufv.br/handle/123456789/2137

Electrochemical degradation of the pharmaceuticals diclofenac sodium, oxytetracycline hydrochloride and chlortetracycline hydrochloride using boron-doped diamond (BDD) anodes were performed in this work. The diamond films were deposited on silicon and niobium cylinders and niobium plates using the chemical vapor deposition (CVD). Characterizations were carried out using scanning electron microscopy (SEM) and Raman spectroscopy. For both substrates, the results indicated polycrystalline diamond and adherent films, without cracks or delamination. Pharmaceuticals were monitored during electrolysis by discrete sampling by analysis of total organic carbon (TOC) and chemical oxygen demand (COD) and continuously by ultraviolet-visible (UV/Vis) spectroscopy. Chemometric methods such as evolving factor analysis (EFA), SIMPLISMA (simple-to-use interactive self-modeling mixture analysis) and multivariate curve resolution-alternating least squares (MCR-ALS) were applied to spectroscopic data to monitoring the degradation kinetics of the original components and their byproducts. Pharmaceuticals were degraded individually and in ternary mixtures. All experiments performed had satisfactory removal of COD, TOC and decrease in absorbance. Significant differences were not observed in respect to substrate shapes on electrodegradation efficiency. The spectra UV/Vis analytical methodology coupled with MCR-ALS method presented to be very promising since it is possible to solve the pure spectra profiles of all the original components in addition to the concentration profiles. Although the resolution obtained, the study was inconclusive in respect to byproducts generated, since a rank deficiency was observed. However, the methodology used for continuous monitoring of the degradation of chemical species that absorb in the UV/Vis range proved to be simple, efficient and reasonably selective for this purpose.