Study on Degradation Law of Several Common Pesticides under Laboratory Conditions
ZHAO Hui-xing et al(Pollution-free Agricultural Products Supervision and Inspection Station in Longgang District of Shenzhen,Shenzhen,Guangdong 518172)
[Objective] The research was to study the degradation law of residual pesticides in pakchoi in different storage conditions.[Method] With common pakchoi as the material,they were soaked in mixed solution with 1 000 times of methyl parathion,dimethoate,dichlorvos,pyralid treat phosphorus,poison-to-death barnyard grass and fenvalerate for 1 min,and then they were saved in CW(25 ℃,humidity 55%RH),LC(4 ℃,humidity 60%RH) and DW(-24 ℃,humidity 70%RH) after air dried.After saved for 0,24,48 and 72 h,the samples from which were taken to determine the residual quantity of pesticides in pakchoi of different treatments.[Result] The degradation speeds of poison-to-death barnyard grass,dichlorvos and methyl parathion in CW were rapid,and they degraded over 50% in 24 h and about 90% in 72 h.The degradation speeds of poison-to-death barnyard grass,dichlorvos and methyl parathion in LC and DW were more rapid than that of others,but slower than that of them in CW.In DW,except the degradation rate of poison-to-death barnyard grass was over 50% in 72 h,the degradation speeds of other pesticides were all slow,the fenvalerate nearly was not degraded.[Conclusion] The degradation speed of each pesticide decreased under the condition of low temperature and cold storage.
【CateGory Index】： X592