Al(III), Cu(II), Co(II), Pb(II), Mn(II), and Fe(III) DETERMINATIONS IN VARIOUS SAMPLES by FAAS AFTER SOLID PHASE EXTRACTION

Abstract

In this study, a novel method for the preconcentration of Al(III), Cu(II), Co(II), Pb(II), Mn(II), and Fe(III) in the form of their hematoxylin chelates using a column filled with Amberlite XAD-16 resin was proposed. Metal chelates collected on the resin were eluted and their determinations were carried out by flame atomic absorption spectrometry (FAAS). The influences of some analytical parameters including pH, flow rate, sample volume, and the type and concentration of eluent on the preconcentration efficiency were examined. The effects of some interfering ions on the recovery values of analytes were also investigated. While the optimum pH value was 8.5 for Cu(II), Co(II), Mn(II), and Fe(III) ions, it was 6.5 for Al(III) and Pb(II) ions. The appropriate eluent for quantitative elution was 8.0 mL of 1 mol/L nitric acid in acetone. Sample and eluent flow rates were found to be 2.0 mL/min. The maximum sample volume was established by changing it from 50 mL to 2500 mL. The sample volume does not significantly affect recovery within the range of 50-2000 mL of the sample volume for the investigated metal ions. The obtained preconcentration factor was 400. At optimum conditions, the detection limits found as concentration which is threefold of the standard deviation of the blank solution were 0.053 g/L, 0.080 g/L, 0.620 g/L, 1.310 g/L, 0.330 g/L and 0.120 g/L for Al(III), Cu(II), Co(II), Pb(II), Mn(II), and Fe(III) ions, respectively, and the adsorption capacities for these ions were 0.47 0.02 mg/g, 0.81 0.01 mg/g, 0.66 0.01 mg/g, 0.58 0.01 mg/g, 0.91 0.01 mg/g, and 0.73 0.02 mg/g, respectively. By using the certified reference materials, the accuracy of the method was verified. The proposed method was successfully applied to cigarette, hair, and some vegetable species.