Study On The Multiresidue Analysis Of Pesticide In Vegetables

The standard method for species of pesticides residue analysis in vegetables by selection of extracting system was studied in this dissertation.The sensitivity and accuracy of the method were investigated.And the applicability in different vegetable matrixes,practicality and applicability of the method were also studied.The main results were summarized as following:Comparing the residue analysis results of organophosphorus pesticides by different sorbents of florisol,alumina and silica gel in column chromatography,we selected florisol as the optimized sorbent.The recoveries of organophosphorus pesticides in vegetable matrix were 5.13～115.00%,and RSD were lower to 20% respectively.The residue analysis results of organophosphorus pesticides by different elute solvents of ethyl acetate,acetone,dichlormethane/ethyl acetate(6/4),dichlormethane / acetonitrile(6/4)and dichlormethane/acetone(6/4)in column chromatography were studied.And dichlormethane/ethyl acetate(6/4)was selected as the optimized elute solvent.The recoveries of organophosphorus pesticides in vegetable matrix were 88.45～118.75%,and RSD were 11.84～19.89%.The multiresidue extraction method based on matrix solid-phase dispersion was optimized with orthogonal design.After optimization of different parameters such as amount of solid phase used,amount of elute solvent used,amount of water solid phase contened and amount of activated carbon used,recoveries at spiked concentrations and relative standard deviation were all accorded with demands of pesticide residue analysis.And the method can be used in pesticides multiresidue analysis in vegetables.The applicability of the optimized method were researched in different matrixes cucumber,tomato,pepper,Chinese chive,spinach and Chinese cabbage.The recoveries of organophosphorus pesticides in vegetable matrix were 88.45～118.75%,and RSD were 80.46～119.65%,and RSD were all lower to 20%except that of diazinon's recovery in Chinese chive.Besides,20 pesticides such as bifenthrin, fipronil etc.were fortified in different concentrations.The recoveries of organophosphorus pesticides in vegetable matrix were 69.94～119.46%,a RSD were all lower to 20%.Compared with the method reported internal,the described procedure is simple, less labour intensive,more cost-effective and environmentally-friendly and dose not required preparation and maintenance of equipment.