title: Optimization and application of homogeneous liquid-liquid extraction in preconcentration of copper (II) in a ternary solvent system.
abstract: In this study a homogeneous liquid-liquid extraction based on the Ph-dependent phase-separation process was investigated using a ternary solvent system (water-acetic acid-chloroform) for the preconcentration of Cu(2+) ions. 8-Hydroxy quinoline was used as the chelating agent prior to its extraction. Flame atomic absorption spectrophotometry using acetylene-air flame was used for the quantitation of analyte after preconcentration. The effect of various experimental parameters in extraction step was investigated using two optimization methods, one variable at a time and central composite design. The experimental design was done at five levels of operating parameters. Nearly the same optimized results were obtained using both methods: sample size, 5 mL; volume of NaOH 10 M, 2 mL; chloroform volume, 300 microL; 8-hydroxy quinoline concentration more than 0.01 M and salt amount did not affect the extraction significantly. Under the optimum conditions the calibration graph was linear over the range 10-2000 microg L(-1). The relative standard deviation was 7.6% for six repeated determinations (C = 500 microg L(-1)). Furthermore, the limit of detection (S/N=3) and limit of quantification (S/N=10) of the method were obtained as 1.74 and 6 microg L(-1), respectively.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran. farajzade@yahoo.com
authors.forename: Mir Ali
authors.initials: MA
authors.lastname: Farajzadeh
authors.forename: Morteza
authors.initials: M
authors.lastname: Bahram
authors.forename: Saioa
authors.initials: S
authors.lastname: Zorita
authors.forename: Behzad Ghorbani
authors.initials: BG
authors.lastname: Mehr
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D002138:Calibration; D002614:Chelating Agents / Q000494:pharmacology; D002725:Chloroform / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D007477:Ions; D008024:Ligands; D015233:Models, Statistical; D015125:Oxyquinoline / Q000737:chemistry; D012972:Sodium Hydroxide / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013054:Spectrophotometry, Atomic / Q000379:methods; D013499:Surface Properties; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical
chemical_list: D002614:Chelating Agents; D007477:Ions; D008024:Ligands; D012997:Solvents; D014874:Water Pollutants, Chemical; D014867:Water; D012972:Sodium Hydroxide; D015125:Oxyquinoline; D003300:Copper; D002725:Chloroform; D019342:Acetic Acid