In this work, core-shell Fe3O4@poly(dopamine) magnetic nanoparticles (m-NPs) were prepared and characterized in our laboratory and applied as sorbents for the magnetic-micro solid phase extraction (m-μSPE) of twelve estrogenic compounds of interest (i.e. 17α-estradiol, 17β-estradiol, estrone, hexestrol, 17α-ethynylestradiol, diethylstibestrol, dienestrol, zearalenone, α-zearalanol, β-zearalanol, α-zearalenol and β-zearalenol) from different water samples. Separation, determination and quantification were achieved by high-performance liquid chromatography coupled to ion trap mass spectrometry with electrospray ionization. NPs@poly(dopamine) were synthesized by a chemical coprecipitation procedure and characterized by different surface characterization techniques (X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, transmission and scanning electron microscopy, infrared and Raman spectroscopy, vibrating sample magnetometry, microelectrophoresis and adsorption/desorption isotherms). Parameters affecting the extraction efficiency of m-μSPE (i.e. polymerization time, pH of the sample, extraction and elution conditions) were studied and optimized. The methodology was validated for Milli-Q, mineral, tap and wastewater using 2-methoxyestradiol as internal standard, obtaining recoveries ranging from 70 to 119% with relative standard deviation values lower than 20% and limits of quantification in the range 0.02-1.1 μg/L.
Keywords: Estrogens; Liquid chromatography; Magnetic nanoparticles; Mass spectrometry; Microdispersive solid-phase extraction; Polydopamine.
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