Core-shell magnetic covalent organic framework nanocomposites as an adsorbent for effervescent reaction-enhanced microextraction of endocrine disruptors in liquid matrices

•Core-shell structrued NiFe2O4@COF MNCs are sucessfully fabricated.•NiFe2O4@COF MNCs possess large specific surface area and pore size over other species.•NiFe2O4@COF MNCs are adopted as an efficient adsorbent for extraction of trace EDs.•CO2-induced dispersion, efficient adsorption and magnetic separation are integrated.•MNER-EM/HPLC-FLD method gives low LOD and high ERs for EDs in real liquid matrices.