Magnetic solid-phase extraction based on octadecyl functionalization of monodisperse magnetic ferrite microspheres for the determination of polycyclic aromatic hydrocarbons in aqueous samples coupled with gas chromatography–mass spectrometry

Monodisperse magnetic C18 microspheres were prepared based on the three-step reactions of solvothermal reduction, silanization and alkylation. The microspheres are of uniform sizes in the range of 200–260 nm. The structure of synthesized magnetic C18 microspheres was studied by transmission electron microscopy, scanning electron microscopy, X-ray diffraction patterns, element analysis and vibrating sample magnetometry. This material has a high magnetic saturation value of 59 emu g−1 and is easy to manipulate under a magnet. The prepared material was used for the preconcentration of the polycyclic aromatic hydrocarbon in water. The effects of desorption solvent and the amount of adsorbent on the preconcentration were also investigated. The results showed that the developed method was beneficial for the preconcentration of PAHs of middle molecular weight.