摘要
采用液相色谱二极管阵列检测器,分析大田条件下20%噻森铜悬浮剂在铁皮石斛中的消解动态和最终残留,为合理使用农药和制定最终残留提供参考。建立了高效液相色谱测定铁皮石斛中噻森铜残留量的分析方法。样品经硫代硫酸钠溶液衍生化,离心,盐酸净化,乙酸乙酯萃取,高效液相色谱(HPLC-DAD)检测。当噻森铜在铁皮石斛中的添加浓度为1.0、5.0、10.0mg/kg时,平均回收率为91.4%~110.4%,相对标准偏差(RSD)为4.4%~8.0%,符合农药残留试验要求。消解动态试验结果显示,噻森铜在铁皮石斛植株中的消解动态规律符合一级动力学方程,半衰期为5.7~10.0d,属易降解农药。最终残留试验表明,20%噻森铜悬浮剂按有效成分400和600mg/kg施药3次和4次,末次施药后14、21、28d,铁皮石斛样品中噻森铜最终残留量分别为<1.0~8.28mg/kg、<1.0~3.867mg/kg、<1.0~2.727mg/kg。建议在铁皮石斛上使用20%噻森铜悬浮剂时,有效成分用药量280~400mg/kg,最多施药3次,安全间隔期28d。
To provide guidance for the safe use of pesticides and establishing the maximum pesticide residue limits,the residue and degradation dynamics of Saisen Tong 20% SC in dendrobium candidum under field were analyzed by high performance liquid chromatography（HPLC-DAD）.After derivation by sodium thiosulfate solution,the samples were centrifuged,purified by hydrochloric acid,extracted with ethyl acetate and detected by HPLC-DAD.Under the fortified level of1.0、5.0、10.0 mg/kg,the average recovery ranged from 91.4% to 110.4% with the relative standard deviations of 4.4%-8.0%,which is applicable for residual analysis.The degradation of Saisen Tong 20% SC in dendrobium candidum complied with first order kinetics equation.The half-life of Saisen Tong in dendrobium candidum was 5.7-10.0 days,indicating that its degradation in dendrobium candidum was fast and that Saisen Tong belonged to readily degradable pesticide.In the final residue test,Saisen Tong 20% SC were sprayed 3 and 4 times at the rate of of 400 and 600（ai）mg/kg.After 14,21 and 28 days of the last application,the final Saisen Tong residues in dendrobium candidum were〈 1.0-8.28 mg/kg,〈1.0-3.867 mg/kg,〈1.0-2.727 mg/kg,respectively.Saisen Tong 20% SC was recommended to be used on dendrobium candidum at the dosage of 280-400 mg（ai）/kg,with the maximum application frequency of three times and the preharvest interval of 28 days.
作者
梁赤周
虞淼
秦丽
徐永
Liang Chizhou;Yu Miao;Xu Yong;Qin Li(Institute for the Control of Agrichemicals Zhejiang Province, Hangzhou Zhejiang 310020, China;Agricultural Products Quality and Safety Inspection and Monitoring Station of Yuhang Dis- trict, Hangzhou Zhejiang 311100, China)
出处
《农药科学与管理》
CAS
2018年第1期47-52,共6页
Pesticide Science and Administration
关键词
噻森铜
铁皮石斛
残留
消解动态
Saisen Tong
dendrobium candidum
residue
degradation dynamics
