GC Determination of Residual Amounts of 24 Organophosphorous Pesticides in Soybean

Twenty four organophosphorous pesticides (OPP′s) as residues remained in soybean were determined by gas chromatography with flame photometric detector (FPD).The soybean sample was homogeneously extracted with acetonitrile,and the extract was purified by passing through C18 SPE column,active carbon SPE column and florisil SPE column in succession.DB-1701 elastic quartz capillary column was used for separation,and method of external standard was adopted in the GC-FPD determination.Detection limits for the 24 pesticides found were in the range from 0.005 to 0.010 mg·kg-1.Recovery and precision were tested and results of recovery obtained were in the range of 60.7%-115.6%,and values of RSD′s (n=6) were ranged from 1.7% to 11.1%.