Determination of Cu(II) ions by FAAS using on-line flow injection preconcentration on N,N'-bis(2-hydroxy-5-bromo benzyl)-1,2-diiminopropane bonded silica gel

In this study, N,N'-bis(2-hydroxy-5-bromo-benzyl)-1,2-diiminopropane bonded silica gel modified silica gel (HBDAP-SG) was synthesized and characterized. The concentration of Cu(II) ions, which were preconcentrated by the on-line flow injection method using the prepared adsorbent, was determined by atomic absorption spectrometry. In order to optimize the on-line flow injection method, the effects of the sample pH, flow rate and volume, and eluent flow rate, type and volume were investigated. Optimum values were found for sample pH to be 8.5, eluent type to be 0.5 HNO3, sample and eluent flow rates to be 7.5 ml/min. The enrichment factor of the method was calculated as 19.4, the limits of detection and quantitation were calculated as 1.2 and 4.0 mg/L, respectively. The adsorption capacity of HBDAP-SG was found to be 53.3 ± 2.1 mg/g. The accuracy of the on-line flow injection method was evaluated by analyzing the certified standard reference materials of Virginia tobacco leaves (CTA-VTL-2) and water reference sample (NWTM-15,2). Using the developed method, Cu(II) levels were successfully determined in various vegetable samples.