An amino-functionalized magnetic framework composite of type Fe 3 O 4 -NH 2 @MIL-101(Cr) for extraction of pyrethroids coupled with GC-ECD

An amino-functionalized magnetic framework composite of type Fe3O4-NH2@MIL-101(Cr) was synthesized using a solvothermal method. The material was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption, and magnetometry. The composite combines the advantages of amino-modified Fe3O4 and MIL-101(Cr). The presence of amino groups facilitates the fairly specific adsorption of pyrethroids. The composite was employed as a sorbent for magnetic solid phase extraction of five pyrethroids from environmental water samples. Following desorption with acidified acetone, the pyrethroids were quantified by gas chromatography with electron capture detection. The detection limits for bifenthrin, fenpropathrin, λ-cyhalothrin, permethrin, and deltamethrin range from 5 to 9 pg·mL−1. The method is rapid, accurate, and highly sensitive. The molecular interactions and free binding energies between MIL-101(Cr) and the five pyrethroids were calculated by means of molecular docking.