title: Multivariate optimization of ultrasound-assisted extraction for determination of Cu, Fe, Ni and Zn in vegetable oils by high-resolution continuum source atomic absorption spectrometry.
abstract: An assisted liquid-liquid extraction of copper, iron, nickel and zinc from vegetable oil samples with subsequent determination by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) was optimized by applying a full factorial design in two levels and the response surface methodology, Box-Behnken. The effects of the acid concentration and the amplitude, cycle and time of sonication on the extraction of the analytes, as well as their interactions, were assessed. In the selected condition (sonication amplitude = 66%, sonication time = 79 s, sonication cycle = 74%), using 0.5 mol L(-1) HCl as the extractant, the limits of quantification were 0.14, 0.20, 0.21 and 0.04 μg g(-1) for Cu, Fe, Ni and Zn, respectively, with R.S.D. ranging from 1.4% to 3.6%. The proposed method was applied for the determination of the analytes in soybean, canola and sunflower oils.
authors.affiliation: Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-290, Brazil.
authors.forename: Alex S N
authors.initials: AS
authors.lastname: Trindade
authors.affiliation: Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-290, Brazil.
authors.forename: Alailson F
authors.initials: AF
authors.lastname: Dantas
authors.affiliation: Departamento de Ciências Exatas e Tecnológicas, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Ilhéus, Bahia 45662-900, Brazil.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Lima
authors.affiliation: Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-290, Brazil; INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, Bahia 40170-280, Brazil.
authors.forename: Sérgio L C
authors.initials: SL
authors.lastname: Ferreira
authors.affiliation: Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-290, Brazil; INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, Bahia 40170-280, Brazil. Electronic address: lsgt@ufba.br.
authors.forename: Leonardo S G
authors.initials: LS
authors.lastname: Teixeira
mesh_terms: D003300:Copper / Q000032:analysis*; D005229:Fatty Acids, Monounsaturated / Q000737:chemistry; D007501:Iron / Q000032:analysis*; D059625:Liquid-Liquid Extraction; D015999:Multivariate Analysis; D009532:Nickel / Q000032:analysis*; D010938:Plant Oils / Q000737:chemistry*; D000074262:Rapeseed Oil; D013024:Soybean Oil / Q000737:chemistry; D013054:Spectrophotometry, Atomic; D000074242:Sunflower Oil; D015032:Zinc / Q000032:analysis*
chemical_list: D005229:Fatty Acids, Monounsaturated; D010938:Plant Oils; D000074262:Rapeseed Oil; D000074242:Sunflower Oil; D003300:Copper; D009532:Nickel; D013024:Soybean Oil; D007501:Iron; D015032:Zinc
keywords: Determination of metals; HR-CS FAAS; Multivariate optimization; Vegetable oil