Solid phase extraction of Cd(II) and Pb(II) ions based on a novel functionalized Fe3O4@ SiO2 core-shell nanoparticles with the aid of multivariate optimization methodology.

This work describes novel Fe3O4@SiO2 core-shell nanoparticles functionalized with phenyl isothiocyanate and its application in the preconcentration of Cd(II) and Pb(II) ions. The parameters affecting the preconcentration procedure were optimized by a Box-Behnken design through response surface methodology. Three variables (extraction time, magnetic sorbent amount, and pH value) were selected as the main factors affecting the sorption step, while four variables (type, volume and concentration of the eluent; and elution time) were selected as effective factors of elution step in the optimization study. Following the sorption and elution, the ions were quantified by FAAS. The limits of detection were 0.05 and 0.9ngmL(-1) for Cd(II) and Pb(II) ions, respectively. The relative standard deviations were less than 6.4%. The sorption capacity (in mg g(-1)) of this new sorbent is 179 for Cd(II) and 156 for Pb(II). Finally, this nanocomposite was successfully applied to the rapid extraction of trace quantities of heavy metal ions from fish, sediment, soil, and water samples and satisfactory results were obtained.