Novel Uniform Fe₃O₄ Hollow Spheres for Magnetic Solid-phase Extraction of Polycyclic Aromatic Hydrocarbons

A novel magnetic absorbent based on Fe₃O₄ hollow nanospheres was developed for polycyclic aromatic hydrocarbons (PAHs) extraction. Fe₃O₄ hollow nanospheres were prepared by a one-pot facile solvothermal method and its structural properties were characterized by scanning electron microscope (SEM) and analyzer transmission electron microscopy (TEM). It was the first time to use hollow nanospheres which possess high special surface area for magnetic solid-phase extraction (MSPE). The extraction condition of Fe₃O₄ hollow nanospheres and its performance for PAHs was systematically investigated. Besides, its extraction performance also compared with bare Fe₃O₄ nanoparticles. The results indicated the structure with hollow and spherical Fe₃O₄ perform better enrichment ability than that with solid and amorphous ones. The developed MSPE coupled with HPLC method shows good linearity (0.1 - 5 ng/mL) and low detection limits (2.5 - 10 pg/mL) for six PAHs. It also has been executed for the analysis of environmental samples, with recoveries in the range of 84.6 - 97.8%.