Solid-phase extraction of copper(II) in water and food samples using silica gel modified with bis(3-aminopropyl)amine and determination by flame atomic absorption spectrometry

A simple and selective separation and preconcentration method was developed for the determination of Cu(II) ions. This method is based on adsorption of Cu(II) ions from aqueous solution on a bis(3-aminopropyl)amine modified silica gel column and flame atomic absorption spectrometric determination after desorption. Various analytical parameters such as pH, type of eluent solution and its volume, flow rate of sample and eluent, and sample volume were optimized. Effects of some cation, anion, and transition metal ions on the recoveries of Cu(II) ions were also investigated. Cu(II) ions were quantitatively recovered at pH 6; 5.0 mL of 2 M HCl was used as the eluent. The preconcentration factor was found to be 150. The LOD was 0.12 μg/L for Cu(II). The accuracy of the method was confirmed by analysis of Tea Leaves (INCT-TL-1) and Fish Protein (DORM-3) certified reference materials. The optimized method was applied to various water and food samples for the determination of Cu(II).