In this work, a new magnetic sorbent, named Fe3O4@CNF@NNSM, using Fe3O4 nanoparticles modified with cellulose nanofiber (CNF) and 1,2-phenylenediamine Schiff base/melamine (NNSM) applied to extract methyl, ethyl, propyl, and butyl parabens based on magnetic solid-phase extraction method followed by high-performance liquid chromatography-ultraviolet detection. Characterization of synthesized materials was conducted using Fourier-transform infrared spectroscopy, field emission-scanning electron microscopy, X-ray powder diffraction, transmission electron microscope, energy dispersion spectroscopy, and vibrating sample magnetometry. Factors affecting the extraction efficiency were screened with the Plackett-Burman design and then analyzed by the Box-Behnken design. This method exhibited an impressive linear range (0.50–200.00 µg/L R2 > 0.9921), and detection limits of 0.12–0.15 µg/L for mentioned parabens. The Enrichment factors were obtained from 120 to 175. The practical application of this method was confirmed by evaluating analyte recovery from cosmetic products, achieving over 90% recovery and a relative standard deviation of less than 5.1%, demonstrating the proposed method's commendable accuracy and precision.
