Magnetic metal-organic framework-titanium dioxide nanocomposite as adsorbent in the magnetic solid-phase extraction of fungicides from environmental water samples

- Magnetic microspheres containing a SiO2-protected Fe3O4 core, a layer of MOF and TiO2 shell were synthesized.
- The microspheres were used as sorbents for MSPE of fungicides from water samples.
- High extraction efficiency and sensitivity were achieved using the developed method.

In this work, a core-shell Fe3O4@SiO2@MOF/TiO2 nanocomposite was synthesized and used to as adsorbent for magnetic solid-phase extraction (MSPE) of triazole fungicides from environmental water samples. Five triazole fungicides, namely, triadimenol, hexaconazole, diniconazole, myclobutanil, and tebuconazole, were selected as target analytes for MSPE. These analytes were quantitatively adsorbed on microspheres, and the sorbents were separated from the solution by using a magnet. The analytes were desorbed by methanol and determined through liquid-chromatography coupled with tandem mass spectrometry. The extraction parameters affecting the extraction efficiency were optimized through response surface methodology. The limits of detection and limits of quantification for the selected fungicides were 0.19-1.20 ng L−1 and 0.61-3.62 ng L−1, respectively. The proposed method was applied to determine the concentration of fungicides in actual environmental water samples. The accuracy of the proposed method was evaluated by measuring the recovery of the spiked samples. The satisfying recoveries of the four water samples ranged from 90.2% to 104.2%. Therefore, the magnetic metal-organic framework/TiO2 nanocomposite based MSPE is a potential approach to analyze fungicides in actual water samples.