title: Multi-element determination of Cu, Fe, Ni and Zn content in vegetable oils samples by high-resolution continuum source atomic absorption spectrometry and microemulsion sample preparation.
abstract: The aim of this work was to evaluate the microemulsification as sample preparation procedure for determination of Cu, Fe, Ni and Zn in vegetable oils samples by High-Resolution Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS). Microemulsions were prepared by mixing samples with propan-1-ol and aqueous acid solution, which allowed the use of inorganic aqueous standards for the calibration. To a sample mass of 0.5g, 100μL of hydrochloric acid and propan-1-ol were added and the resulting mixture diluted to a final volume of 10mL. The sample was manually shaken resulting in a visually homogeneous system. The main lines were selected for all studied metals and the detection limits (3σ, n=10) were 0.12, 0.62, 0.58 and 0.12mgkg(-1) for Cu, Fe, Ni and Zn, respectively. The relative standard deviation (RSD) ranged from 5% to 11 % in samples spiked with 0.25 and 1.5μgmL(-1) of each metal, respectively. Recoveries varied from 89% to 102%. The proposed method was applied to the determination of Cu, Fe, Ni and Zn in soybean, olive and sunflower oils.
authors.affiliation: Instituto de Química,Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-290, Brazil.
authors.forename: Luana S
authors.initials: LS
authors.lastname: Nunes
authors.forename: José T P
authors.initials: JT
authors.lastname: Barbosa
authors.forename: Andréa P
authors.initials: AP
authors.lastname: Fernandes
authors.forename: Valfredo A
authors.initials: VA
authors.lastname: Lemos
authors.forename: Walter N L Dos
authors.initials: WN
authors.lastname: Santos
authors.forename: Maria Graças A
authors.initials: MG
authors.lastname: Korn
authors.forename: Leonardo S G
authors.initials: LS
authors.lastname: Teixeira