Solid phase extraction of Pd(II) ions byTris(2-aminoethyl)amine bonded silica gel anddetermination with flame AAS

In this study, tris(2-aminoethyl)amine bonded silica gel (Tris-SG) was synthesized and used as an adsorbent for solid phase extraction of Pd(II) ions from aqueous solutions. Throughout the study, flame atomic absorption spectrometer was used for the determination of Pd(II) concentrations. The effects of acid and chloride concentration in the sample solution, and contact time and initial Pd(II) concentration on Pd(II) adsorption were investigated and optimized in the experiments performed by the batch adsorption method. Pd(II) adsorption was found to be maximum from solution containing 0.1 M C1- and 0.1 M HNO3. Pd(II) adsorption equilibrium was reached at 240 min. Experimental Pd(II) adsorption capacity of tris(2-aminoethyl)amine bonded silica gel was found to be 71.8 mg/g. In column SPE studies, the effective factors such as sample volume, flow rate of sample, type, flow rate and volume of the eluent solution and levels of some alkaline and heavy metals were examined and optimized. It was found that Pd(II) ions were quantitatively recovered using the Tris-SG filled column by passing of 1000 mL of the sample solution containing 0.1 M C1- and 0.1 M HNO3 at 10 mL/min flow rate thorough the column and then elution of adsorbed Pd(II) ions with 5 mL of 1.0 % thiourea in 1.0 M HCl solution using 10 mL/min flow rate. Limit of detection and quantitation limits for Pd (II) were calculated as 0.21 and 0.68 µg/L, respectively, using 200 enrichment factors obtained in the developed method. The accuracy of the method was determined by palladium determination in certified reference material of platinum ore coded SARM7B. The developed method was successfully determined Pd(II) levels in various water samples by spiking and recovery experiments, and percent recoveries of Pd(II) were obtained in the range of 97 to 107 %.