Magnetic mesoporous polymelamine-formaldehyde resin as an adsorbent for endocrine disrupting chemicals (Publication with Expression of Concern. See vol. 185, 2018)

A magnetic mesoporous poly(melamine-formaldehyde) composite (Fe3O4-mPMF) was prepared via grafting poly(melamineformaldehyde) onto the surface of amino-functionalized magnetite (Fe3O4) nanoparticles. The material was characterized by scanning electron micrography, transmission electron microscopy, X-ray diffraction, Fourier transform-infrared spectroscopy, nitrogen adsorption-desorption isotherms, and thermogravimetric analysis. It has a large surface area, a typical mesoporous structure, and a high thermal stability. It was employed as a magnetic sorbent for the solid phase extraction of the following endocrine disrupting chemicals (EDCs): Bisphenol A, 4-tert-butylphenol, 4-tert-octylphenol and nonylphenol. The EDCs were then quantified by HPLC. Under the optimized conditions, the response to the EDCs is linear in the range of 0.5-100 ng.mL(-1), and the limits of detection are 0.02-0.1 ng.mL(-1). The high adsorption capability of the Fe3O4-mPMF is mainly attributed to multiple interactions including pi-stacking, hydrogen bonding, and hydrophobic interactions. The method was applied to the extraction of EDCs from spiked river water and bottled juice samples. The results demonstrated that the Fe3O4-mPMF is an efficient adsorbent for the extraction of organic compounds with large conjugated pi-system, plenty of hydrogen-bonding sites, and strong hydrophobicity.