Development of a new cloud point extraction determination method for trace metal determination in aqueous solutions and application to environmental samples

In this study, environmentally friendly, low cost, effective and easily applicable Cloud Point Extraction (CPE) methods were developed using previously synthesized and not used for analytical purposes organic ligands (L1-L4) in the separation and preconcentration of trace elements such as Cu(II), Pb(II), Cd(II), Co(II), Cr(III), Cr(VI), Ni(II), Pd(II), Pt(IV) and Au(III) from aqueous solutions. When the data were evaluated; it was determined that the L1 ligand could be utilized for Cu(II), Ni(II), Pb(II) and Cd(II) ions at pH 7.0, the L2 ligand for Pb(II) ions at pH 8.0, the L3 ligand for Cu(II)ions at pH 7.0 and the L4 ligand for the separation and preconcentration of Co(II), Cr(III), Cu(II), Ni(II) and Pb(II) ions at pH 7.0. In order to determine the optimum experimental conditions of CPE methods, the effects of analytical parameters such as pH, ligand amount, surfactant concentration, incubation time and temperature, centrifugation speed and time on recovery efficiency were investigated in detail. The effects of various anion and cation species, which may be present in food and water samples analyzed for trace elements and could cause interference, on the recovery process were investigated. The analytical performance of the methods was evaluated in terms of limit of detection (LOD), limit of quantification (LOQ), and relative standard deviation (RSD%). After determining the optimum conditions of the experimental parameters for each method, analyte addition/recovery studies were carried out to the water and food sample matrix for method validation. The developed methods were successfully applied for the separation and preconcentration of Cd(II), Co(II), Cr(III), Cu(II), Ni(II) and Pb(II) ions from the complex matrix before their determination by flame atomic absorption spectrophotometric method from water samples such as stream water, sea and tap water and food samples such as lettuce, parsley, pepper, pear, apricot, carrot, cherry, peach, apple, rice, bulgur and lentil.