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Use este identificador para citar ou linkar para este item: https://repositorio.ufba.br/handle/ri/6018
Tipo: Artigo de Periódico
Título: Pre-concentration procedure for determination of copper and zinc in food samples by sequential multi-element flame atomic absorption spectrometry
Título(s) alternativo(s): Talanta
Autor(es): Ferreira, Hadla S.
Santos, Ana C. N.
Portugal, Lindomar Andrade
Costa, Antonio Celso Spinola
Miró, Manuel
Ferreira, Sergio Luis Costa
Autor(es): Ferreira, Hadla S.
Santos, Ana C. N.
Portugal, Lindomar Andrade
Costa, Antonio Celso Spinola
Miró, Manuel
Ferreira, Sergio Luis Costa
Abstract: In this paper is proposed a simultaneous pre-concentration procedure using cloud point extraction for the determination of copper and zinc in food samples employing sequential multi-element flame atomic absorption spectrometry (FS-FAAS). The reagent used is 1-(2-pyridylazo)-2-naphthol (PAN) and the micellar phase is obtained using the non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) and centrifugation. The optimization step was performed using Box–Behnken design for three factors: solution pH, reagent concentration and buffer concentration. A multiple response functionwas established in order to get an experimental condition for simultaneous extraction of copper and zinc. Under the optimized experimental conditions, the method allows the determination of copper with a limit of detection (3 b/S, LOD) of 0.1 gL−1, precision expressed as relative standard deviation (R.S.D.) of 2.1 and 1.3% (N= 10), for copper concentrations of 10 and 50 gL−1, respectively. Zinc is determined with a LOD of 0.15 gL−1 and precision as R.S.D. of 2.7 and 1.7% for concentrations of 10 and 50 gL−1,respectively. The enhancement factors obtained were 36 and 32 for copper and zinc, respectively. The accuracy was assessed by analysis of certified reference materials, namely, SRM 1567a – Wheat Flour and SRM 8433 – Corn Bran from National Institute of Standards & Technology and BCR 189-wholemeal flour from Institute of Reference Materials and Measurements. Themethodwas applied to the determination of copper and zinc in oats, powdered chocolate, corn flour and wheat flour samples. The copper content in the samples analyzed varied from1.14 to 3.28 gg−1 and zinc from 8.7 to 22.9 gg−1.
Palavras-chave: Zinc
Copper
Food samples
Cloud point
Box–Behnken design
URI: http://www.repositorio.ufba.br/ri/handle/ri/6018
Data do documento: 2008
Aparece nas coleções:Artigo Publicado em Periódico (Química)

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