Solid phase extraction containing multi-walled carbon nanotubes and eggshell membrane as adsorbent for ICP-OES determination of Pb(II) and Cd(II) in various water and orange fruit (peel and pulp) samples

Multi-walled carbon nanotubes (MWCNTs) functionalized with soluble eggshell membrane protein (SEP) bio-polymer were prepared as a novel adsorbent for solid phase extraction and ICPOES determination of Pb(II) and Cd(II). This material was characterized by FTIR, TG-DTA, DSC, and XRD. Also, a new dithiocarbamate chelating agent derived from barbituric acid was prepared and characterized by FTIR, 1HNMR, and elemental analysis. Various factors influencing the preconcentration of lead and cadmium ions such as pH, sample and eluent flow rates, concentration and type of eluents, sample volume, chelating agent concentration and interfering ions were investigated. The accuracy of the method was confirmed with the standard addition method. The limits of detection (LODs) for this method were found to be 0.10 μg L ^-1 and 0.073 μg L ^-1 for Pb(II) and Cd(II), respectively. The relative standard deviation (RSD) was 1.2% for lead and 1.0% for cadmium, with a preconcentration factor of 25. The optimized method was applied to various water and orange fruit (peel and pulp) samples.