title: Monosegmented flow analysis exploiting aqueous two-phase systems for the determination of cobalt.
abstract: An environmentally safe procedure has been developed for the extraction, separation and determination of metal ions using a monosegmented flow analysis technique that exploits an aqueous two-phase system (ATPS-MSFA).  The ATPS-MSFA method was applied for the determination of cobalt, based on the reaction between Co(II) and KSCN, which produces a metallic complex that spontaneously partitions to the top phase of the ATPS composed of poly(ethylene oxide), ammonium sulfate and water.  The linear range was 5.00 to 500 μmol kg(-1) (R = 0.9998; n = 13) with a coefficient of variation equal to 1.14% (n = 7).  The method yielded a limit of detection and a limit of quantification of 2.17 and 7.24 μmol kg(-1), respectively.  The ATPS-MSFA method was applied to the determination of cobalt in a nickel-cadmium battery sample and the results were validity with flame atomic absorption spectrometry using addition standard.
authors.affiliation: Grupo de Química Verde Coloidal e Macromolecular, Departamento de Química, Centro de Ciências Exatas e Tecnológicas, Universidade Federal de Viçosa, Brazil.
authors.forename: Guilherme Dias
authors.initials: GD
authors.lastname: Rodrigues
authors.forename: Leandro Rodrigues
authors.initials: LR
authors.lastname: de Lemos
authors.forename: Luis Henrique Mendes
authors.initials: LH
authors.lastname: da Silva
authors.forename: Maria C Hespanhol
authors.initials: MC
authors.lastname: da Silva
mesh_terms: D003035:Cobalt / Q000032:analysis*; D017022:Flow Injection Analysis; D013861:Thiocyanates / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D013861:Thiocyanates; D014867:Water; D003035:Cobalt