Study On Multiresidue Analysis Of Organophophorus Insecticides In Vegetable

In order to compare the retention time (RT) and limits of detection of 20 organophosphorous insecticides in different conditions the experiments were carried out using a medium polar capillary column (DB-1701) and a no polar capillary column (DB-1) with two detectors (GC-FPD and NPD). The RT of 20 organophosphorous insecticides in two different polar capillary columns was a retention qualitative method for 20 organophosphorous insecticides. DB-1701 capillary column coupled with GC-FPD detector was used in the following study, the limits of detection were in range of 5x10-11~2X 10-12 g, the linear range was 2X 10-9~1 X 10-11g .Multi-residue analysis of 20 organophosphorous insecticides in vegetable was performed by DB-1701 capillary column coupled with GC-FPD detector in this study. Ethyl acetate was used to extract the pesticides from vegetable samples using a homogenizer. The extract was separated, concentrated and detected by GC-FPD. Recoveries were in range of 73% ~ 121 %. Limits of quantification for different pesticides were in range of 0.002~0.05mg/kg. The relative standard deviations were in range of 0~16.2%.A study was carried out to clean up interferences from vegetable samples(cabbage and shallot) for multi residue analysis of 20 organophosphorous insecticides in vegetable. Recoveries from three different chromatographic cleaning-up columns(fiorisil, neutral alumina and charcoal)were studied. The interferences from cabbage and shallot can be removed effectively by florisil or neutral alumina column and charcoal column respectively.The residue of 9 organophosphorous insecticides in vegetable in kunming ,Yunnan province was detected using the multi-residue method. The residue of 9 organophosphorous insecticides was detected in 51 of 152 vegetables. The residue of 34.2% samples was higher than their MRL.