Magnetic mesoporous polymelamine-formaldehyde resin as an adsorbent for endocrine disrupting chemicals

Abstract

A magnetic mesoporous poly(melamine-formaldehyde) composite (Fe₃O₄-mPMF) was prepared via grafting poly(melamine-formaldehyde) 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 π-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 π-system, plenty of hydrogen-bonding sites, and strong hydrophobicity. Graphical abstract A magnetic mesoporous polymelamine-formaldehyde composite (Fe₃O₄-mPMF) was prepared and employed as a magnetic sorbent for the solid phase extraction of endocrine disrupting chemicals from river water and bottled juice samples prior to high-performance liquid chromatographic analysis.

Keywords: Adsorption mechanism; Bottled juice; Fourier transform infrared spectra; High-performance liquid chromatography; Magnetic adsorbent; Magnetic solid phase extraction; Powder X-ray diffraction; River water; Transmission electron microscopy; X-ray photoelectron spectroscopy.