Magnetic metal-organic framework MIL-100 (Fe)/polyethyleneimine composite as an adsorbent for the magnetic solid-phase extraction of fungicides and their determination using HPLC-UV.

FeO@MIL-100 (Fe)/PEI are used for the first time as an adsorbent material for the extraction of pesticide residues (epoxiconazole, flusilazole, tebuconazole, and triadimefon) from food matrices. The adsorbent proposed (FeO@MIL-100(Fe)/PEI) was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), thermogravimetric (TG) analysis, and vibrating sample magnetometer (VSM) techniques to evaluate the properties of the sorbent. Then, the FeO@MIL-100 (Fe)/PEI was employed for the quantification of the four triazole fungicides in fruits and vegetables (apple, orange, tomato, cabbage, and cucumber) using HPLC-UV for separation and detection.

Magnetic solid-phase extraction based on nano-zeolite imidazolate framework-8-functionalized magnetic graphene oxide for the quantification of residual fungicides in water, honey and fruit juices.

In this work, zeolite imidazolate framework-8 (ZIF-8) functionalized magnetic graphene oxide (FeO@APTES-GO/ZIF-8) was successfully synthesized and used as a novel adsorbent in magnetic solid-phase extraction (MSPE) for the determination of four triazole fungicides in water, honey and fruit juices. The main parameters such as extraction time, amount of adsorbent, the pH value of the sample, ionic strength, and desorption solvent which could affect the experiment results were optimization. Under the optimum condition, the obtained linearity of this method ranged from 1 to 1000 µg L for all analytes, with correlation coefficients (R) ≥ 0.