喹啉铜在西瓜和土壤中残留及消解动态

目的]为评价50%多抗·喹啉铜可湿性粉剂在西瓜上使用安全性。方法]利用超高效液相色谱-光电二极管阵列检测器(UPLC-PDA)对山东和浙江2年2地的西瓜和土壤中的喹啉铜残留消解动态及最终残留进行了测定和研究。用高剂量喹啉铜562.5 g a.i./hm^2喷施后2 h,1、3、5、7、10、14、21 d取样进行西瓜和土壤残留消解动态测定。用喹啉铜375、562.5 g a.i./hm^2分别喷施3次和4次,喷药后5、7、10 d取样进行全瓜、瓜肉和土壤最终残留测定。结果]50%多抗·喹啉铜在西瓜和土壤中的消解动态曲线均符合一级动力学方程,半衰期分别为1.1~2.5、1.4~2.3 d,最终残留试验结果表明当喹啉铜施药量为375、562.5 g a.i./hm^2,施药次数为3次和4次时,距最后1次施药7 d后喹啉铜在西瓜全瓜、瓜肉和土壤的残留量均<0.20 mg/kg。结论]50%多抗·喹啉铜可湿性粉剂属于易降解农药,在结果初期开始施用,施药剂量不高于562.5 g a.i./hm^2,次数不多于4次,施药间隔不小于5 d,西瓜上建议采收安全间隔期为7 d。试验为喹啉铜在西瓜上安全使用提供了理论依据。

Residue and Dissipation Dynamics of Oxine-copper in Watermelon and Soil

Aims]In order to evaluate the safety of muti-resistance oxine-copper 50%wettable powder in watermelon and soil.Methods]Propose a ultra-performance liquid chromatography coupled to photodiode array detection(UPLC-PDA)method to detect oxine-copper.Decline and residue of oxine-copper 50%were investigated in field experiments in Shandong and Zhejiang for two years.In degradation dynamics experiment,oxine-copper 50%with high dose(562.5 g a.i./ha)were sprayed to watermelon and soil,respectively.The representative samples(watermelon and soil)were collected at 2 h,1,3,5,7,10,14,21 d after 50%oxine-copper treatment.In the residue experiment,oxine-copper 50%with high dose(562.5 g a.i./ha)and low dose(375 g a.i./ha)were sprayed for 3 and 4 times to watermelon in the early stages of cirsoid blight.The representative samples(watermelon and sarcocarp)were collected at 5,7,10 d after the last spray.Results]As time went on,the residual contents of oxine-copper in the watermelon and soil decreased,which accorded with the first-order kinetics equation.The results showed that the half-lives of oxine-copper in watermelon and soil were 1.1-2.5 and 1.4-2.3 days,respectively.In the residue experiment,following the recommended dosage of oxine-copper(375 and 562.5 g a.i./ha)which were sprayed 3 and 4 times,the watermelon collected at the 7 th day after the last application.The final residues of oxine-copper were not detected(oxine-copper content<0.200 mg/kg).Oxine-copper is easily degraded in watermelon and soil which is environment friendly pesticide.Conclusions]Muti-resistance oxine-copper 50%wettable powder is easily degraded in watermelon and soil which is environment friendly pesticide.The safety interval of muti-resistance oxine-copper 50%wettable powder for watermelon is 7 days under the conditions that in fruiting early stage,the dosage is not higher than 562.5 g a.i./ha,the frequency is not more than 4 times,and the spraying interval is not less than 5 d.The experiment results provide data support for the safe use of oxine-copper in watermelon.