Determination of Diflubenzuron and Hexaflumuron in Fruits by High Performance Liquid Chromatography with Online Polymeric Monolithic Column Solid phase Extraction

KeyWord:benzoylurea insecticides  polymer based monolithic column  online solid phase extraction  high performance liquid chromatography£¨HPLC£©  fruit

Abstract:

      A method based on high performance liquid chromatography£¨HPLC£© with online monolithic column solid phase extraction was developed for the determination of diflubenzuron and hexa flumuron in fruits. The polymer£¨poly£¨2 ethylhexyl methacrylate co ethylene dimethacrylate£©£© monolithic column£¨10 mm¡Á4ª±6 mm£¬iª±d.£© was prepared by using 2 ethylhexyl methacrylate£¨EHMA£© as monomer and ethylene dimethacrylate£¨EDMA£© as crosslinker£¬which exhibited a porous structure with a specific surface area of 164ª±01 m2¡¤g-1. Using polymer monolithic column as online solid phase extraction sorbent£¬the extracted fruit sample solution was loaded into the monolithic column using 5 mmol¡¤L-1 NH4OAc at a flow rate of 0ª±1 mL¡¤min-1. The adsorbed analytes were transferred from monolithic column to the analytical column using acetonitrile-water£¨65¡Ã35£¬by volume£© as mobile phase at a flow rate of 1ª±0 mL¡¤min-1. Under the optimized conditions£¬there was a good linearty for the method in the range of 0ª±1-50ª±0 mg¡¤L-1£¨r¡Ý0ª±998£©. The limits of detection and quantitation for diflubenzuron and hexaflumuron were 0ª±007 2 mg¡¤kg-1 and 0ª±009 mg¡¤kg-1£¬and 0ª±024 mg¡¤kg-1 and 0ª±030 mg¡¤kg-1£¬respectively. The recoveries at three spiked levels of 0ª±03£¬0ª±3 and 1ª±5 mg¡¤kg-1 were in the range of 89ª±5%-102% with intra day and inter day relative standard deviations not more than 6ª±8%.