Double-functionalized magnetic nanoparticles for preconcentration and determination of polycyclic aromatic hydrocarbons in water samples

A rapid and simple method for the separation and determination of five polycyclic aromatic hydrocarbons (PAHs) in water is described. The procedure is based on the selective extraction of the PAHs on the surface of modified magnetic nanoparticles using a solid-phase dispersion technique. The PAHs-loaded magnetic nanoparticles were separated from the aqueous phase with a magnet and then quantified by HPLC. The modified extraction method successfully replaced conventional extraction methods. The partitioning of the analyte between the sub-micron magnetic nanoparticles (solid phase) and the liquid phase occurs as the solid moves through the samples as a colloidal sol. The detection limits were in the range 0.14-0.31 ng/L, with recoveries ranging from 88% to 96%. The as-synthesized magnetic nanoparticles showed good stability and high extraction recoveries for the adsorption-desorption of PAHs, even after recycling four times. The procedure was successfully applied to PAHs determinations in real water samples.