A method of high performance liquid chromatography(HPLC) with magnetic solid phase extraction(MSPE) was developed for the determination of four benzoylurea pesticides

ie.forchlorfenuron

penfluron

hexaflumuron and lufenuron in irrigation water.A magnetic metal organic framework sorbent(Fe3O4-NH2@MIL-101) was fabricated via solvothermal method.The composition and morpholgy of the composite were characterized by scanning electron microscopy（SEM）

Fourier transform infrared spectroscopy(FT-IR) and X ray diffraction（XRD) analysis.Meanwhile

the magnetic intensity of the material was detected with a vibrating sample magnetometer.The determination of four analytes was performed by HPLC with the synthesized composite as MSPE adsorbent.The adsorption and elution factors，including adsorbent amount

adsorption time

pH value

elution time and elution volume

were investigated.Under the optimum conditions

the calibration curves for four benzoylurea pesticides showed good linear relationships in the range of 0.010-3.0 mg/L with correlation coefficients(r) higher than 0.999 5.The detection limits and the quantitation limits were in the ranges of 0.03-0.09 μg/L and 0.10-0.30 μg/L

respectively.The recoveries at three spiked levels ranged from 81.7% to 95.4% with RSD less than 10%.With a simple pretreatment process and an extraction time within 15 min

the method could be applied in the analysis on trace residues of benzoylurea pesticides in irrigation water.