Extraction of Trace Amounts Copper (II) Using Octadecyl Silica Membrane Disks Modified Isocyanate-Treated GOs (iGOs)

Abstract

A number of functionalized graphite oxides were prepared by treatment of graphite oxide (GO) with organic isocyanates. A simple and reproducible method for the rapid extraction and determination of trace amounts of copper (II) ions using octadecyl-bonded silica membrane disks modified by isocyanate-treated GOs (iGOs) and Atomic Absorption Spectrometry is presented. The method is based on complex formation on the surface of the ENVI-18 DISK disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution is efficient and quantitative. The effect of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about 1000mL providing a preconcentration factor of 500. The maximum capacity of the disks was found to be 389± 4 μg for Cu.The limit of detection of the proposed method is 5ng per 1000mL.The method was applied to the extraction and recovery of copper in different water samples.