Study On Determination Of Strobilurin Fungicides Residues In Some Fruits And Vegetables

In this study, a gas chromatography-mass spectrometry method have been developed with particularity for determining strobilurin fungicides in some fruits and vegetables.Now their MRLs are established by American, Canada, Europe union and so many countries or some related international organization. But in china, there is the blank in MRLs and latent harm of residue.In according to the structure and property of strobilurin fungicide, the instrument was point out and the tentative plan was bring forward. Many experiments were done for strobilurin fungicides residue. Sampling weight and extract way were determined. Three clean-up method were compared. And the mass spectrum was analyzed emphatically. The selected icons and their proportion was confirmed. The mass database of strobilurin fungicides was founded.The experiment indicated that GPC bring on the effective purification and concentration. This method can reduce disturbance of the complex sample background, Its pretreatment condition was as follows: The samples were extracted with ethyl acetate-cyclohexane on ultrasonic for 10 min, centrifuge for 5 min at 4000 r/min, then anhydrous sodium sulfate was used to dehydrate, dry and reconstitute. The extraction was cleaned-up by GPC, eluted by acetate-cyclohexane, and collected fraction between 11-16min. Strobilurin fungicides residue in vegetables and fruits were determined by gas chromatography-mass spectrometry (GC/MS) with selected-ion monitoring (SIM). Recoveries of fortified samples were ranged from 80.28% to 103.92%,and RSD ranged from 2.45%to 12.22%. The eleven strobilurin fungicides can separate one by one. The method saved the solvent, time and cost, it can get high recovery. The limits of detection were 0.001 to 0.005mg/kg, the minimum detection limit was lower than international MLRs of strobilurin fungicides.