农药喷施浓度对厚皮甜瓜套袋果实中残留量的影响

Influence of Pesticide Concentration on the Residues of Bag-covered Melon

为明确不同施药浓度对不同厚皮甜瓜品种套袋果实中的农药残留量的影响及药残富集部位,以厚皮甜瓜金玉和M135为试材,对不套袋、套白纸袋的果实喷施不同稀释倍数的多菌灵和敌敌畏药剂,分别采用高效液相色谱法(HPLC)和气相色谱法(GC)测定农药的残留量。结果表明,果实样品中的多菌灵和敌敌畏残留量分别在施药后第5天和第1天达到最高,最高值分别为0.599mg·kg-1和0.786mg·kg-1,农药残留量随施药浓度的变化而呈现不同的变化趋势。残留的农药主要集中在果实外果皮,其中外果皮中多菌灵残留量占全部的70.4%,敌敌畏占38.8%。由此说明,套袋对不同浓度的农药作用效果不一致,对高浓度药剂能够起到良好的阻隔效果,而对低浓度的药剂作用不显著,且不同类型农药在果实中的分布与药剂性质存在相关性。

The influence of different pesticide concentration on the changes and enrichment sites of pesticide residues in the bagged fruit of melon varieties Jinyu and M135 were studied. The bagged and no bagged fruits were sprayed with different dilutions of Carbendazim and Dichlorovos（DDVP）and the residues were to determine by GC and HPLC. On the 1st and 5th day after spraying,the residues of Carbendazim and DDVP in fruits reached to the highest,the highest value was 0.599 mg·kg-1 and 0.786 mg·kg-1,respectively. The pesticide residues showed different trends with the changes of pesticide concentration. Pesticide residues were mainly concentrated in the epicarp. Carbendazim residues in epicarp accounted for 70.4%,DDVP for 38.8%. The experiment showed that the effect of bagging on the different pesticide concentrations was not the same. Bagging of fruit can play a good barrier for high concentration spray but less effect to the low concentration spray. The distribution of pesticides residues in fruit was related to nature of the chemicals.