title: A preconcentration procedure for the determination of cadmium in biological material after on-line cloud point extraction.
abstract: In this paper, a method involving on-line preconcentration with cloud point extraction for the determination of cadmium in biological samples is presented. The procedure is based on the sorption of micelles containing Cd(II) ions and the reagent 4-(5'-bromo-2'-thiazolylazo)orcinol (Br-TAO) in a minicolumn packed with polyester. The surfactant Triton X-114 was used in the formation of micelles. After sorption, the Cd(II) ions were desorbed from the minicolumn with acid eluent and determined by flame atomic absorption spectrometry. Parameters influencing the cloud point extraction were studied. The method showed a detection limit of 0.5 μg l(-1) and an enhancement factor of 27. The accuracy was tested by determination of cadmium in certified reference materials (spinach leaves 1570a and tomato leaves 1573a) from the National Institute of Standards and Technology.
authors.affiliation: Universidade Federal do Espírito Santo, Departamento de Ciências Matemáticas e Naturais, Rodovia BR 101 Norte, Km 60, Litorâneo, 29932-540, São Mateus, Espírito Santo, Brazil.
authors.forename: Patrícia Xavier
authors.initials: PX
authors.lastname: Baliza
authors.forename: Luiz Augusto Martins
authors.initials: LA
authors.lastname: Cardoso
authors.forename: Valfredo Azevedo
authors.initials: VA
authors.lastname: Lemos
mesh_terms: D002104:Cadmium / Q000032:analysis* / Q000737:chemistry; D005591:Chemical Fractionation / Q000379:methods; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry; D008823:Micelles
chemical_list: D004785:Environmental Pollutants; D008823:Micelles; D002104:Cadmium