title: Synthesis of a new solid-phase extractor and its application to preconcentration and determination of lead in water samples.
abstract: A procedure for preconcentration and determination of lead in water is described. The method is based on the sorption of Pb(II) in a minicolumn packed with a functionalized sorbent and subsequent elution with acidic solution. The determination of lead content in the eluate was carried out using flame atomic absorption spectrometry. The sorbent was prepared by immobilization of the ligand 4-(5'-bromo-2'-thiazolylazo)orcinol on polystyrene-divinylbenzene through an azo spacer. Diazotization and coupling reactions were used for synthesis of the sorbent. Some variables affecting the preconcentration were optimized using a full factorial design. Under optimized conditions, the method presented a detection limit of 0.5 microg/L and enrichment factor of 36 for a sample volume of 25 mL. The accuracy of the method was tested by the determination of lead in a standard reference material (National Institute of Standards and Technology 1643d Fresh Water). The proposed procedure was applied to the determination of lead in samples of natural and drinking waters.
authors.affiliation: Universidade Federal da Bahia, Instituto de Química, Campus Universitário de Ondina, 40.170-280 Salvador, Bahia, Brazil.
authors.forename: Cleber Galvão
authors.initials: CG
authors.lastname: Novaes
authors.forename: Juracir Silva
authors.initials: JS
authors.lastname: Santos
authors.forename: Sérgio Luís Costa
authors.initials: SL
authors.lastname: Ferreira
authors.forename: Valfredo Azevedo
authors.initials: VA
authors.lastname: Lemos
mesh_terms: D007854:Lead / Q000032:analysis*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D007854:Lead