[Preparation of MIL-53(Fe)@polydopamine@FeO magnetic composite for magnetic solid-phase extraction of sulfonylurea herbicides in environmental water].

Polydopamine (PDA) and MIL-53(Fe) modified FeO particles (MIL-53(Fe)@PDA@FeO magnetic composite) were prepared by simple one-pot solvothermal method. The obtained composite was introduced to rapidly extract four kinds of sulfonylurea herbicides (SUHs) from environmental water samples by magnetic solid-phase extraction (MSPE). Then the herbicides were analyzed by a high performance liquid chromatographic system equipped with a photodiode array detector. The mobile phase was a mixture of acetonitrile and water containing 0.01% (v/v) trifluoroacetic acid, and the detection wavelength was 233 nm. Significant extraction parameters were optimized to improve the extraction efficiency. Under the optimum conditions (5 mL desorption solvent of acetone, 4.5 min extraction time, 60 mg adsorbent dosage, 0.5 g NaCl and the pH 3 of the solution), the developed method showed good linearities with correlation coefficients () no less than 0.9980. The limits of detection (LODs, =3) of the four SUHs were 0.28-0.77 μg/L. The method was successfully used to determine four SUHs in three kinds of environmental water samples with satisfactory recoveries ranging from 78.8% to 109.7%. Therefore, the MIL-53(Fe)@PDA@FeO magnetic composite is efficient and has good potential for the extraction of SUHs.