Study on column SPE with nano synthesized graphene oxide and FAAS for determination of trace amount of Co(II) and Ni(II) ions in real samples

A selective method for the preconcentration and separation of trace amounts of Co(II) and Ni(II) by columnsolid phase extraction has been developed. The method is based on the adsorption of metal ions as N-(5-methyl-2-hydroxyacetophenone)-N'-(2-hydroxyacetophenone) ethylene diamine (MHE) complex on synthesized graphene oxide.Computational modeling based on PM6 semi-empirical potential energy surface was utilized to investigate the interactionof metallic complexes with graphene oxide sheet. The adsorption was achieved quantitatively on graphene oxide at pH6.0 and then the retained analyte contents on the column were quantitatively eluted with 3.0 mol L-1 HNO3. Experimentalconditions for effective separation of trace levels of the analyte ions such as pH, flow rate, concentration of eluent, samplevolume and interference ions were investigated. A preconcentration factor of 250 was achieved by passing 1250 mL ofsample through the solid phase, while the limit of detection of Co(II) and Ni(II) ions were found to be 0.25 and 0.18 ngmL-1, respectively. The method was applied to the determination of analyte ions in water, black tea and tomato samples.

کلیدواژه ها:

Cobalt ، Nickel ، Solid Phase Extraction ، Nano Graphene Oxide ، Flame Atomic Absorptions Spectrometry