Determination of trace metals in sediments by preconcentration as Xanthogenate complex on activated carbon/AAS

The selective adsorption of metal ions with activated carbon(AC) and potassium o-ethyl dithiocarbonate (potassium Xanthogenate) was studied for the preconcentration of traces of Cd(II), Pb(II), Cu(II) and Co(II) ions. To the sample solution of about 100 cm³, 120 mg of potassium Xanthogenate and 50 mg of AC were added, and the mixture was stirred for 20 min in a ultrasonication bath and filtered. AC was heated with 1 cm³ of concentrated nitric acid. After nitric acid was evaporated, adsorpted metals were desorbed in the bath using 5 cm3 of 3 mol dm⁻³ nitric acid and the AC was removed by filtration. The concentrations of the metal ions in the solution were measured by AAS. The proposed method was successfully applied to the determination of the trace metals in bottom sediments such as pond(NIES, No. 2), river and marine environment by AAS. The results obtained for pond sediment were in excellent agreement with certified values. This method is very simple, and suitable for the determination of trace amounts of Cd, Cu, Pb and Co in the sample containing large amounts of Fe and Al.