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

• We use a synthesized graphene oxide for preconcentration of Co(II) and Ni(II) ions.
• Adsorption mechanism was investigated by PM6 semi-empirical potential energy surface.
• LODs were found to be 0.25 and 0.18 ng mL− 1 for Co and Ni, respectively.
• The preconcentration factor is 250 and ion separation is so fast.
• It is applied to the determination of Co and Ni ions in real samples.

A selective method for the preconcentration and separation of trace amounts of Co(II) and Ni(II) by column solid 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 interaction of metallic complexes with graphene oxide sheet. The adsorption was achieved quantitatively on graphene oxide at pH 6.0 and then the retained analyte contents on the column were quantitatively eluted with 3.0 mol L− 1 HNO3. Experimental conditions for effective separation of trace levels of the analyte ions such as pH, flow rate, concentration of eluent, sample volume and interference ions were investigated. A preconcentration factor of 250 was achieved by passing 1250 mL of sample 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 ng mL− 1, respectively. The method was applied to the determination of analyte ions in water, black tea and tomato samples.

The SPE procedure of Co(II) and Ni(II) as their N-(5-methyl-2-hydroxyacetophenone)-N′-(2-hydroxyacetophenone) ethylene diamine complex and FAAS determination was developed for separation and preconcentration of mentioned ions.Figure optionsDownload as PowerPoint slide