Removal Effects And Detection Of Six Kinds Of Residual Pesticide In Fruits Or Vegetables

In order to effectively remove the residual pesticides in fruits or vegetables and other agricultural products, to ensure the food safety, protect people’s healthy, with the help of HPLC and GC to analysis, the Removal effects and influencing factors of several common pesticide in fruits or vegetables degradated by oxy-cleaning is systematically studied, and made a preliminary analysis of its mechanism.the main results are listed as follows:1Through a large number of experiments, a fast, simple and effective HPLC-UV and GC detection method have been established and used to detect the residual pesticides in the six kinds of fruits or vegetables and waste waters with pesticides.When the added concentration were1,10,50mg/kg, the average recoveries of triazophos,difenoconazole,deltamethrin in strawberry and pakchoi cabbage ranged from85.21%to94.51%,the relative standard deviation ranged from1.36%to5.19%, when added concentration were1,10,30mg/kg, the average recoveries of chlorpyrifos in strawberry and pakchoi cabbage ranged from84.72%to88.89%,its relative standard deviation ranged from2.45%to5.19%,when added concentration were5,10,50mg/kg, the average recoveries of cypermethrin in sweet bean angle ranged from94.18%to98.44%, its relative standard deviation ranged from0.55%to1.25%. The accuracy precision and sensitivity of this analysis can meet the requirements of residual pesticide detection.Thus this method can adapt to sample analysis and detection in large-scale field.2Studied the effect factors and degradation efficiency of oxy-cleaning, by changing the dosage, pH, concentration of pesticides, washing time, washing water conditions. the results showed that,Based on daily life practical washing conditions,setting the washing temperature of30℃, the hard water concentration of250mg/kg,the detergent concentration of0.8%, the washing time for immersion in2min,8min under uniform washing, have a better effective washing method.of oxy-cleaning.3The Removal effects of oxy-cleaning by different molecular structure properties and characters of pesticides were studied,results showed that, for fruits or vegetables which surface area is greater than the other,oxy-cleaning has a good degradation effect,conversely,the fruit or vegetable with a smooth surface has a low primitive accumulation,the degradation effect is not so obviously.oxy-cleaning has a better degradation effect for organic phosphorus pesticides.A preliminary analysis of Oxy-cleaning pesticide removal mechanism was made. Oxy-cleaning in water can effectively degrade organic phosphorus pesticides (e.g., chlorpyrifos, Triazophos) with P=S molecular structure.And dichlorvos,cypermethrin and deltamethrin which pesticide molecular structure containing halogen elements Cl and Br, were hard to be degraded completely.