Extraction of four endocrine-disrupting chemicals using a Fe3O4/graphene oxide/di-(2-ethylhexyl) phosphoric acid nano-composite, and their quantification by HPLC-UV

•A novel adsorbent based on Fe3O4/GO/DEHPA nanocomposite (NC) was introduced.•The prepared NC was used for the pre-concentration of four endocrine-disrupting chemicals.•The optimization of effective variables was performed using a response surface methodology.•Quantification of the pre-concentrated analytes was carried out by HPLC.•The method was applied to assess the target analytes in breast milk, urine and water samples.