Magnetic iron(III)-based framework composites for the magnetic solid-phase extraction of fungicides from environmental water samples.

We adopted a facile hydrofluoric acid-free hydro-/solvothermal method for the preparation of four magnetic iron(III)-based framework composites (MIL-101@Fe3 O4 -COOH, MIL-101-NH2 @Fe3 O4 -COOH, MIL-53@Fe3 O4 -COOH, and MIL-53-NH2 @Fe3 O4 -COOH). The obtained four magnetic iron(III)-based framework composites were applied to magnetic separation and enrichment of the fungicides (prochloraz, myclobutanil, tebuconazole, and iprodione) from environmental samples before high-performance liquid chromatographic analysis. MIL-101-NH2 @Fe3 O4 -COOH showed more remarkable pre-concentration ability for the fungicides as compared to the other three magnetic iron(III)-based framework composites. The extraction parameters affecting enrichment efficiency including extraction time, sample pH, elution time, and the desorption solvent were investigated and optimized. Under the optimized conditions, the standard curve of correlation coefficients were all above 0.991, the limits of detection were 0.04-0.4 μg/L, and the relative standard deviations were below 10.2%. The recoveries of two real water samples ranged from 71.1-99.1% at the low spiking level (30 μg/L). Therefore, the MIL-101-NH2 @Fe3 O4 -COOH composites are attractive for the rapid and efficient extraction of fungicides from environmental water samples.