Bilayer Surfactants of Fatty Acid and Cetyltrimethylammonium Bromide on Magnetic Nanoparticles for Preconcentration of Polycyclic Aromatic Hydrocarbons in Water Samples

Abstract

In this work, the highly dispersible sorbent in aqueous media, bilayer surfactants of fatty acid (FA) and cetyltrimethylammonium bromide (CTAB) coated on magnetic nanoparticles (MNPs), Fe3O4@FA@CTAB NPs, was synthesized successfully. It was used as sorbent for magnetic solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) in water samples. The extraction conditions including sorbent quantity, sample volume, adsorption time, elution solvent, and desorption time were investigated. The synthesized Fe3O4@FA@CTAB NPs could provide a high preconcentration factor and well dispersion in water samples because of the hydrophilic property of bilayer surfactants on MNPs. The extracted PAHs (phenanthrene, anthracene, and fluoranthrene) were determined by HPLC–UV technique using Waters Nova-Pak® C18 column and a mixture of acetonitrile, methanol, and deionized water (30/40/30) as mobile phase. The synthesized magnetic sorbent and the developed HPLC method were applied to determine PAHs in water samples. The extraction recoveries of PAHs in river water samples were achieved in the range of 71.78–118.29% with the RSD less than 4.70%. The limit of detection were 0.67, 0.10, and 0.53 μg L−1 for phenanthrene, anthracene, and fluoranthene, respectively. The results demonstrate that the developed method is suitable for rapid, simple, and inexpensive determination of PAHs in water samples.