硝酸稀土对菠菜中毒死蜱残留的降解作用研究

Effects of Rare Earths Nitrate on Degradation of Chlorpyrifos Residue in Spinach

菠菜是我国蔬菜出口的重要品种之一,其毒死蜱残留量直接关系到我国农产品的出口和消费者的安全。采用气相色谱法(GC-NPD)测定毒死蜱残留量,研究了硝酸稀土对菠菜中毒死蜱残留动态的影响。结果表明,不论是喷施农药之前2d还是喷施农药之后2d喷施硝酸稀土,不同的硝酸稀土对菠菜中的毒死蜱残留都有不同程度的降解作用,且随着喷药后时间的延长,毒死蜱在菠菜中的残留量逐渐减少。不同时间喷施硝酸稀土,对菠菜中毒死蜱残留降解的效果存在差异,药后喷施的效果优于药前喷施。在硝酸稀土种类的选择上,首先选择对毒死蜱降解效果好的硝酸铈和硝酸钕,其次选择常乐益植素和硝酸镧。根据稀土农用的安全性分析,参考植物性食品中稀土最大残留限量标准,选择硝酸稀土作为农药残留降解制剂用于蔬菜安全生产,在技术上是可行的,人类食用是安全的。

Spinach （Spinacia oleracea L. ） is an important variety for the vegetable export in China. The chlorpyrifos residue in spinach is directly related to the export trade of agricultural products and safety of consumer. In this work, the residue of chlorpyrifos was determined by GC（ Gas Chromatograph ） with NPD detector. The dynamic analysis of chlorpyrifos residue in spinach sprayed with rare earths nitrate was also carried out. The results indicated that the different rare earths nitrate help to reduce the pesticide residue in spinach, whether 2 d before or after spraying pesticide. However, different degradation efficiencies of chlorpyrifos were found when the spinach was treated with different rare earths nitrate. After spraying, the concentration of chlorpyrifos residue in spinach decreased with keeping time delayed. For different time of spraying, degradation effects of rare earths nitrate on chlorpyrifos residue in spinach presented diverse, on the whole, the effect of spraying after pesticide application is superior to that before application. Cerium nitrate and neodymium nitrate showed the best degradation effects on chlorpyrifos residue in spinach, and lanthanum nitrate and changleyizhisu took second place. On the basis of safety analysis for rare earth application to farming, and consulting maximum residue limits for rare earth in vegetable food, as a result, applying rare earths nitrate as degradation preparation for pesticide residues will be feasible and helpful for the security growth of vegetables.