摘要
【目的】研究阿维菌素通过土壤穴施施药方式在黄瓜和土壤中的残留消解动态,制定阿维菌素缓释粒剂防止黄瓜根结线虫的安全间隔期。【方法】阿维菌素消解动态试验采用推荐高剂量的1.5倍(5.62 g·m-2)为施药剂量,在黄瓜移栽时通过土壤穴施方式施药1次。分别测定施药后2 h、1 d、3 d、5 d、7 d、10 d、14 d、21 d、28 d和45 d的阿维菌素残留量的变化。阿维菌素的最终残留试验设置高低两个不同施药剂量:低剂量按推荐剂量3.75 g·m-2,高剂量按推荐剂量的1.5倍(5.62 g·m-2),分别于黄瓜移栽时土壤穴施1次,于黄瓜成熟期采样测定阿维菌素的最终残留量。样品中阿维菌素残留量的测定采用分散固相萃取-液相色谱-串联质谱法(LC-MS/MS)法,在10 g粉碎均质的黄瓜、植株或土壤样品加入4 g无水硫酸钠和1 g氯化钠,用10 mL乙腈提取2 min后,离心并移取上清液2 mL,通过50 mg N-丙基乙二胺吸附剂(PSA)和50 mg十八烷基键合硅胶吸附剂(C18)进行分散固相萃取(DSPE)净化,离心上清液过0.22μm滤膜后上机测定。【结果】本文所建立的阿维菌素残留量的分散固相萃取-液相色谱-串联质谱测定法简单快速,阿维菌素在10、50和100μg·kg-1 3个添加水平下回收率为78%—101%,相对标准偏差1.9%—9.4%;方法定量限为10.0μg·kg-1,该方法能够满足现有限量标准的要求。北京和哈尔滨两个试验点消解动态试验中,采用土壤穴施施药方式,阿维菌素在黄瓜中未检出,这表明阿维菌素是非内吸性农药;而在土壤中检出了阿维菌素,其降解动态符合一级动力学指数模型,在土壤中的半衰期为7.9—18.7 d。在黄瓜最终残留试验中,成熟期的所有黄瓜样品中均未检出阿维菌素。在土壤最终残留试验中,2012年北京试验点的3个样品检出阿维菌素,检出浓度分别为10、30和170μg·kg-1;哈尔滨试验点的2个土壤样品检出阿维菌素,检出浓度均为10μg·kg
[ Objective ] The objective of this study is to study the degradation dynamics of abamectin in cucumber and soil, and to formulate a scientific basis for the reasonable dose and the pre-harvest interval on controlling cucumber root-knot nematode with hole application. [Method] Degradation dynamics experiments were conducted by application abamectin once on cucumber and soil with hole application at 5.62 g·m2 （1.5 times recommended dosage） after transplanting cucumber seedlings. Degradation dynamics samples were collected and determined at random from each plot at different time intervals i.e, 0 day （2 h after application）,1, 3, 5, 7, 10, 14, 21, 28, and 45 days after the abamectin application. Two doses were set in terminal residue experiment. Abamectin was applied once at 3.75 g·m-2 （low concentration, recommended dosage） and 5.62 g.m2 （high concentration, 1.5 times recommended dosage） after transplanting period of cucumber seedlings. Terminal residue samples were collected and determination of abamectin during the harvesting periods. The dispersive solid phase extraction-high performance liquid chromatography-tandem mass spectrometry （LC-MS/MS） method was used to determine the abamectin residue in cucumber and soil. The homogenized cucumber samples, plant samples or soil samples （10 g） were firstly weight into a polypropylene centrifuge tube. After adding 4 g Na2SO4, and 1 g NaC1, the sample was extracted by 10 mL acetonitrile. Secondly, the extraction solution was sonicated and centrifuged for several minutes. Then 2 mL of the clarified supematant was transferred into a clean centrifuge tube containing 50 mg of C18 and 50 mg PSA dispersive solid phase extraction （DSPE） sorbents for purification. Finally, the solution filtered through a 0.22 μm membrane prior to LC-MS/MS analysis. [ Result ] The established method for determination of abamectin in cucumber and soil with DSPE combined LC-MS/MS was rapidly and easy of operation. The recoveries of abamectin in cucumber and soil were
出处
《中国农业科学》
CAS
CSCD
北大核心
2014年第18期3684-3690,共7页
Scientia Agricultura Sinica
基金
科技基础性工作专项(2013FY110100)
农药登记残留试验项目(2011P180)
关键词
阿维菌素
液相色谱-串联质谱
分散固相萃取
降解
残留
土壤穴施
abamectin
high performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS）
dispersive solid phase extraction
degradation
residue
hole application
