Abstract

A novel, sensitive and effective method has been developed for preconcentration of Ni on C₁₈ disks modified cyclodextrin–chitosan/nano graphene oxide. Simple chemical bonding method to synthesize cyclodextrin–chitosan/nano graphene oxide (CCGO) was reported. The adsorption behaviors of Ni (II) in aqueous solution on CCGO were systematically investigated. The procedure is based on the selective formation of Ni(II) at optimum pH by elution with organic eluents and determination by flame atomic absorption spectrometry. The method is based on complex formation on the surface of the ENVI-18 DISK^TM disks modified CCGO 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, CCGO amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about 1000 ml providing a preconcentration factor of 600. The maximum capacity of the disk modified CCGO was found to be 398±3 µg for Ni²⁺. The limit of detection of the proposed method is 5 ng per 1000 ml. The method was applied to the extraction and recovery of Ni in different water samples.

Key words: Ni(II), octadecyl slica disk (SPE), flame atomic absorption spectrometric (FAAS), cyclodextrin–chitosan/nano graphene oxide (CCGO).