Determination of Residual Organophosphorus Pesticides in Ham by Gas Chromatography with Purification on Gel Permeable Column

Ham sample was extracted with acetonitrile,and the organophosphorus pesticides in the extract were purified by passing through the gel permeable column (GPC).Elution was carried out with cyclohexane-ethyl acetate (1+1) mixture as eluant,and the eluate collected from the 100th-165th mL was taken for GC determination of 9 pesticides.Flame photometric detection (FPD) and external standard method were adopted in the quantitative analysis.DB-1701 capillary chromatographic column (30 m×0.53 mm,i.d.1.0 μm) was used in the GC-separation,with the column temperature at 250 ℃,and the detector temperature at 230 ℃.Flow-rate of the carrying gas (N2) taken was 10 mL·min-1.Limit of quantification of triazophos was found to be 2.8 μg·kg-1,while for the other 8 pesticides,the values found were all 5 μg·kg-1.Recovery test of all these pesticides were done and results obtained were above 70%.