title: Determination of manganese in water samples by flame atomic absorption spectrometry after cloud point extraction.
abstract: Cloud point extraction has been used for the preconcentration of manganese, after the formation of a complex with 1-(2-thiazolylazo)-2-naphthol (TAN), and later analysis by flame atomic absorption spectrometry using octylphenoxypolyethoxyethanol (Triton X-114) as surfactant. The chemical variables affecting the separation phase and the viscosity affecting the detection process were optimized. Under the optimum conditions (i.e., pH = 9.2, [TAN] = 2.0 x 10(-5) mol l-1, [Triton X-114] = 0.05%, added methanol volume = 0.2 ml), preconcentration of 50 ml of sample solution permitted the detection of 0.28 ppb for manganese. The enhancement factor was 57.6. The proposed method has been applied to the determination of manganese in water samples.
authors.affiliation: Division of Chemistry, Natural Sciences, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616. kcteo@nie.edu.sg
authors.forename: K C
authors.initials: KC
authors.lastname: Teo
authors.forename: J
authors.initials: J
authors.lastname: Chen
mesh_terms: D001391:Azo Compounds; D007202:Indicators and Reagents; D008345:Manganese / Q000032:analysis*; D017830:Octoxynol; D011092:Polyethylene Glycols; D013054:Spectrophotometry, Atomic; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D001391:Azo Compounds; D007202:Indicators and Reagents; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C054556:1-(2-thiazolylazo)-2-naphthol; D011092:Polyethylene Glycols; D008345:Manganese; D017830:Octoxynol; C010615:Nonidet P-40