title: Multivariate optimization of simple procedure for determination of Fe and Mg in cassava starch employing slurry sampling and FAAS.
abstract: A slurry sampling procedure has been developed for Fe and Mg determination in cassava starch using flame atomic absorption spectrometry. The optimization step was performed using a univariate methodology for 200mg samples and a multivariate methodology, using the Box-Behnken design, for other variables, such as solvent (HNO3:HCl), final concentration (1.7molL-1) and time (26min). This procedure allowed determination of iron and magnesium with detection limits of 1.01 and 3.36mgkg-1, respectively. Precision, expressed as relative standard deviation (%RSD), was of 5.8 and 4.1% (n=10) for Fe (17.8mgkg-1) and Mg (64.5mgkg-1), respectively. Accuracy was confirmed by analysis of a standard reference material for wheat flour (NIST 1567a), which had certified concentrations of 14.1±0.5mgkg-1for Fe and 40±2.0mgkg-1for Mg, and the concentrations found using proposed method were 13.7±0.3mgkg-1for Fe and 40.8±1.5mgkg-1for Mg. Comparison with concentrations obtained using closed vessel microwave digestion was also realized. The concentrations obtained varied between 7.85 and 17.8mgkg-1for Fe and 23.7-64.5mgkg-1, for Mg. The simplicity, easily, speed and satisfactory analytical characteristics indicate that the proposed analytical procedure is a good alternative for the determination of Fe and Mg in cassava starch samples.
authors.affiliation: Universidade Estadual de Santa Cruz, Departamento de Ciências Exatas e Tecnológicas, Rodovia Jorge Amado km 16, Salobrinho, CEP 45662-900 Ilhéus, Bahia, Brazil. Electronic address: facamorim@uesc.br.
authors.forename: Fábio Alan Carqueija
authors.initials: FA
authors.lastname: Amorim
authors.affiliation: Universidade Estadual de Santa Cruz, Departamento de Ciências Exatas e Tecnológicas, Rodovia Jorge Amado km 16, Salobrinho, CEP 45662-900 Ilhéus, Bahia, Brazil.
authors.forename: Vinicius Câmara
authors.initials: VC
authors.lastname: Costa
authors.affiliation: Universidade Estadual de Santa Cruz, Departamento de Ciências Exatas e Tecnológicas, Rodovia Jorge Amado km 16, Salobrinho, CEP 45662-900 Ilhéus, Bahia, Brazil.
authors.forename: Erik Galvão P da
authors.initials: EG
authors.lastname: Silva
authors.affiliation: Universidade Estadual de Santa Cruz, Departamento de Ciências Exatas e Tecnológicas, Rodovia Jorge Amado km 16, Salobrinho, CEP 45662-900 Ilhéus, Bahia, Brazil.
authors.forename: Daniel de Castro
authors.initials: DC
authors.lastname: Lima
authors.affiliation: Universidade Estadual de Santa Cruz, Departamento de Ciências Exatas e Tecnológicas, Rodovia Jorge Amado km 16, Salobrinho, CEP 45662-900 Ilhéus, Bahia, Brazil.
authors.forename: Raildo Mota de
authors.initials: RM
authors.lastname: Jesus
authors.affiliation: Universidade Estadual do Sudoeste da Bahia, Departamento de Química e Exatas, Rua José Moreira Sobrinho s/n, Jequiezinho, Jequié/BA 45206-190, Brazil.
authors.forename: Marcos de Almeida
authors.initials: MA
authors.lastname: Bezerra
mesh_terms: D005433:Flour / Q000032:analysis; D005506:Food Contamination / Q000032:analysis*; D007501:Iron / Q000032:analysis*; D008274:Magnesium / Q000032:analysis; D002365:Manihot / Q000737:chemistry*; D008872:Microwaves; D013054:Spectrophotometry, Atomic / Q000379:methods*; D013213:Starch / Q000032:analysis*; D014908:Triticum / Q000737:chemistry
chemical_list: D013213:Starch; D007501:Iron; D008274:Magnesium
keywords: Box-Behnken design; Cassava starch; Iron; Magnesium; Slurry sampling