Comparison of the sorption capacities of 1,10-phenanthroline and 2,2-bipyridyl complexes with cadmium on activated carbon and graphene oxide

Abstract

In this study adsorption potential of oxidation activated carbon (ox-AC) and graphene oxide (GO) was investigated. Cd(II) was bound to cationic complexes with 1,10-phenanthroline or 2,2-bipyridyl. The sorbents have been used for the dispersive solid-phase extraction of Cd(II) prior to its inductively coupled plasma optical emission spectrometric or electrothermal atomic absorption spectrometric determination. The influences of the various analytical parameters including pH, eluent type, ligand amount, sample volume and sorption time on the recovery efficiencies of Cd(II) were investigated. The limit of detection for activated carbon - 1,10-phenanthroline and activated carbon - 2,2-bipyridyl were 0.006 and 0.016 ng mL−1, respectively. For graphene oxide with 1,10-phenanthroline and graphene oxide with 2,2-bipyridyl obtained limit of detection were 0.046 and 0.091 ng mL−1, respectively. Maximum adsorption capacities and preconcentration factors were compared. The equilibrium sorption fitted better to the Langmuir isotherm. The method was validated with the certified reference materials ERM-BB186 and SRM 1640a.