Preparation and application of Fe3O4@ SiO2@ poly (o-phenylenediamine) nanoparticles as a novel magnetic sorbent for the solid-phase extraction of tellurium in water samples and its determination by ET-AAS

•A novel sorbent was easily synthesized and used to extract tellurium from aqueous samples.•Nano Fe3O4@ SiO2@ poly(o-phenylenediamine) sorbent was used for the extraction.•Unlike many reported works, no evaporation of the solvent was used after desorption step.•13 parameters pertaining synthesis, extraction and desorption were optimized.•Good linear range, detection limit, standard deviation and recovery was obtained.