title: Flotation separation and electrothermal atomic absorption spectrometric determination of thallium in wastewater samples.
abstract: The proposed method is a simple process for the determination of trace amount of thallium(I) in the environmental wastewater samples by electrothermal atomic absorption spectrometry. The wastewater samples were obtained from the environment of a cement plant and subjected to a simple treatment, such as adjusting pH and masking the interfering ions, to prepare for the flotation process in which the thallium(I) content was floated as an ion-association complex using iodide and Rhodamine B at the interface of aqueous/cyclohexane layers. The floated layer was then separated and dissolved in 2 ml of a solution, which was 1% to H2SO4 and 50% to methanol, respectively. Aliquots of 10-microl of this solution were subjected to the graphite furnace to determine the thallium(I) content. The flotation process can be carried in a weak acidic medium in which the interfering effects owing to certain metal ions were eliminated by masking them as neutral citrate chelates. The dynamic range for the determination was found to be 1.0 x 10(-8) - 1.0 x 10(-7) mol l(-1). The RSD was 3.2% and the DL was 2.5 x 10(-9) mol l(-1) (calculated as 3SD of the blank). The reliability of the method is demonstrated by the analysis of a synthetic wastewater in which the recovery was found to be 94%.
authors.affiliation: Department of Chemistry, Faculty of Science, University of Birjand, P.O. Box 79, Birjand, Iran. MSHosseini@birjand.ac.ir
authors.forename: Mohammad Saeid
authors.initials: MS
authors.lastname: Hosseini
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Chamsaz
authors.forename: Heidar
authors.initials: H
authors.lastname: Raissi
authors.forename: Yousef
authors.initials: Y
authors.lastname: Naseri
mesh_terms: D002614:Chelating Agents / Q000737:chemistry; D002951:Citrates / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007454:Iodides / Q000737:chemistry; D012235:Rhodamines / Q000737:chemistry; D012722:Sewage / Q000032:analysis* / Q000737:chemistry; D013054:Spectrophotometry, Atomic / Q000379:methods*; D013696:Temperature; D013793:Thallium / Q000032:analysis* / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002614:Chelating Agents; D002951:Citrates; D007220:Industrial Waste; D007454:Iodides; D012235:Rhodamines; D012722:Sewage; D014874:Water Pollutants, Chemical; D006108:Graphite; D013793:Thallium; C029773:rhodamine B