Multivariate technique for optimization of digestion procedure by focussed microwave system for determination of Mn, Zn and Fe in food samples using FAAS

• Autor(a) principal: Bezerra, Marcos de Almeida
• Data de Publicação: 2006
• Outros Autores: Ferreira, Sergio Luis Costa, Santelli, Ricardo Erthal, SantAna, Otoniel Domingos de, Cassella, Ricardo Jorgensen
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFBA
• Texto Completo: http://www.repositorio.ufba.br/ri/handle/ri/12783
• topic: Multivariate optimization; Doehlert matrix; Iron; Zinc; Manganese; FAAS

This article describes the development by response surface methodology (RSM) of a procedure for iron, zinc and manganese determination by flame atomic absorption spectrometry (FAAS) in food samples after digestion employing a focussed microwave system. A Doehlert matrix was used to find optimal conditions for the procedure through response surface study. Three variables (irradiation power and time and composition of oxidant solution—HNO3 + H2O2) were regarded as factors in the optimization study. The working conditions were established as a compromise between optimum values found for each analyte taking into consideration the robustness of the procedure. These values were 12 min, 260 W and 42% (v/v) for irradiation time, irradiation power and percent of H2O2 in solution, respectively. The accuracy of the optimized procedure was evaluated by analysis of certified reference materials and by comparison with a well-established closed vessel microwave dissolution methodology.