Preconcentration of Pb(II), Cu(II) and Cd(II) ions by carrier element free coprecipitation method and their determination with AAS

The organic ligand, 2-(2-Bromobenzyl)-1H-Benzimidazole (BOB), has been utilized for the first time in this thesis as an organic coprecipitant for the development of a new carrier element free coprecipitation method (CEFC) to separate and preconcentrate the various heavy metal ions from water and food samples prior to their determination by flame atomic absorption spectrophotometer (FAAS). The recovery efficiency of the analyte ions has been investigated in terms of substantial experimental factors including solution pH, BOB quantity, standing time, centrifuge speed and duration and volume of sample and these parameters were optimized as 8.0, 4.0 mg, 5 min, 3000 rpm, 3 min, and 100 mL, respectively. A preconcentration factor of 25, detection limit of 7.27, 2.56 and 2.01 µg L–1 for Pb(II), Cd(II) and Cu(II) ions, respectively with relative standard deviation lower than 4% were obtained for the developed process. It was observed that several anions and cations in the real sample matrix did not cause a serious interference effect on the recovery of the analyte ions. After being tested the method accuracy with analyte addition/recovery studies, the suggested fast, selective, low-cost and environmentally friendly CEFC method has been successfully carried out for the determination of Pb(II), Cd(II) and Cu(II) levels in river and sea waters and in various food samples such as cabbage, eggplant and parsley.