实验室条件下几种常见农药降解规律研究

[目的]研究不同储存条件下小白菜中残留农药的降解规律。[方法]以普通小白菜为材料,将其在1 000倍甲基对硫磷、乐果、敌敌畏、治螟磷、毒死稗和氰戊菊酯的混合稀释液中浸泡1 min,取出晾干后分别在CW（25℃,湿度55%RH）、LC（4℃,湿度60%RH）和DW（-24℃、70%RH）条件下保存,0、24、48、72 h后分别取样,测定各处理小白菜中农药的残留量。[结果]CW条件下毒死稗、敌敌畏、甲基对硫磷降解速度较快,24 h降解50%以上,72 h降解90%左右;LC和DW条件下毒死稗、敌敌畏、甲基对硫磷的降解速度较其他几种农药快,但较在CW条件下降解慢;DW条件下除毒死稗72 h降解率超过50%外,其他几种农药降解较慢,氰戊菊酯几乎没有降解。[结论]低温冷藏条件下,各农药降解速度均下降。

Study on Degradation Law of Several Common Pesticides under Laboratory Conditions

[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.