Rapid and Simultaneous Determination of Organophosphorus Pesticides in Agricultural Products by FPD-GC

Abstract

A method for rapid and simultaneous determination of 19 kinds of organophosphorus pesticides was developed by FPD-GC with two kinds of capillary columns (DB-5MS and DB-210). Sample preparation of the 19 pesticides in agricultural products was systematically established as follows. 1) Pesticides in vegetables and fruits were extracted with acetone, re-extracted with dichloromethane, and determined by GC. 2) Pesticides in onion were extracted with acetone by homogenation of a frozen sample in dilute phosphoric acid, and re-extracted with dichloromethane. 3) Pesticides in soybean, redbean and hulled rice were extracted with 30% aqueous acetone, then cleaned up with zinc acetate in order to remove some of the components, including fatty acids, as a precipitate, and re-extracted with dichloromethane. 4) Pesticides in green tea were extracted and re-extracted by the same method as in 3). Then the dichloromethane extract was concentrated to dryness, and the residue obtained was extracted with n-hexane in order to remove insoluble components.Recoveries and coefficients of variation of the pesticides in all agricultural products were in the ranges of 46.7-120% and 0.1-14.9%, respectively.