摘要
[目的]建立高效液相色谱-串联双质谱(LC-MS/MS)法检测油茶中325 g/L苯甲·嘧菌酯悬浮剂的残留分析方法,研究其消解动态和最终残留量。[方法]油茶样品用乙腈提取,QuEChERs法净化,采用Agilent Eclipse plus C18色谱柱,以0.1%甲酸-乙腈和0.1%甲酸水溶液为流动相测定试样中苯醚甲环唑和嘧菌酯的含量。[结果]在0.01~1.0 mg/kg添加水平下,测得苯醚甲环唑和嘧菌酯在油茶中的添加回收率分别在88%~95%和94%~97%之间,相对标准偏差分别为2.2%~3.8%和1.8%~3.5%,检出限(LOD)为0.001 mg/kg,定量限(LOQ)为0.01 mg/kg。湖南地区苯醚甲环唑和嘧菌酯在油茶中的残留消解动态符合一级动力学方程,降解半衰期分别为4.7、6.3 d。在4个试验地中,325 g/L苯甲·嘧菌酯悬浮剂在末次用药后21 d均可降解至0.01 mg/kg以下,符合膳食要求。[结论]推荐325 g/L苯甲·嘧菌酯悬浮剂的有效成分用药量为406.25 g a.i./hm^(2),施药次数为3次,采收安全间隔期为14 d,施药间隔期为7 d。
[Aims] This study aims to establish a high performance liquid chromatography-tandem double mass spectrometry(LC-MS/MS) method for the determination of difenoconazole-azoxystrobin 325 g/L(suspension concentrate, SC) in Camellia oleifera. The degradation dynamics and final residues were studied. [Methods] The samples were extracted with acetonitrile, purified by QuEChERs method, an Agilent Eclipse Plus C18 column was used to determine the contents of difenoconazole and azoxystrobin with 0.1% formic acid-acetonitrile and 0.1% formic acid aqueous solution as mobile phases. [Results] The recoveries of difenoconazole and azoxystrobin in C. oleifera were88-95 and 94-97% at the supplemental level of 0.01-1.0 mg/kg with the relative standard deviations of 2.2-3.8 and1.8-3.5%, respectively. The limits of detection(LOD) was 0.001 mg/kg and the limit of quantification(LOQ) was0.01 mg/kg. The degradation dynamics of difenoconazole and azoxystrobin in C. oleifera in Hunan province were in accordance with the first-order kinetic equation, and the degradation half-lives were 4.7 and 6.3 d, respectively. In the four experimental sites, the difenoconazole-azoxystrobin 325 g/L SC could be degraded to less than 0.01 mg/kg after21 d of the last treatment, which met the dietary requirements. [Conclusions] The recommended dosage of active ingredient for difenoconazole-azoxystrobin 325 g/L SC was 406.25 g a.i./ha, the application times were 3 times, the safe harvest interval was 14 d, and the application interval was 7 d.
作者
李佳星
袁静
周沙
陈杰
LI Jia-xing;YUAN Jing;ZHOU Sha;CHEN Jie(College of Forestry and Biotechnology,Zhejiang A&F University,Hangzhou 311300,China)
出处
《农药》
CAS
CSCD
北大核心
2022年第2期123-126,共4页
Agrochemicals
基金
国家自然科学基金项目(32001316)
浙江省重点研发项目(2021C02046)。
关键词
油茶
苯醚甲环唑
嘧菌酯
消解动态
残留
Camellia oleifera
difenoconazole
azoxystrobin
degradation dynamics
residue
