Magnetic solid-phase extraction of five pyrethroids from environmental water samples followed by ultrafast liquid chromatography analysis

► Polystyrene-coated magnetic nanoparticles (MNPs/PSt) were prepared. ► The MNPs/PSt were used for magnetic solid-phase extraction (MSPE) of pyrethroids. ► The MSPE showed good selectivity and efficiency. ► The MNPs/PSt can be recycled.