中国农业科学

• 专题:农产品安全 • 上一篇    下一篇

阿维菌素在黄瓜和土壤中的残留及其消解动态

金芬,王静,魏闪闪,杜欣蔚,邵华,金茂俊,王珊珊,佘永新   

  1. 中国农业科学院农业质量标准与检测技术研究所/农业部农产品质量安全重点实验室,北京 100081
  • 收稿日期:2014-03-31 修回日期:2014-05-27 出版日期:2014-09-16 发布日期:2014-09-16
  • 通讯作者: 王静,Tel:010-82106568;E-mail:w_jing2001@126.com
  • 作者简介:金芬,Tel:010-82106570;E-mail:jinfenbj@163.com
  • 基金资助:
    科技基础性工作专项(2013FY110100)
    农药登记残留试验项目(2011P180)

Degradation Dynamics and Residues Analysis of Abamectin in Cucumber and Soil

JIN Fen, WANG Jing, WEI Shan-shan, DU Xin-wei, SHAO Hua, JIN Mao-jun, WANG Shan-shan, SHE Yong-xin   

  1. Institute of Quality Standard and Testing Technology for Agri-products, Chinese Academy of Agricultural Sciences/Key Laboratory of Agrifood Safety and Quality, Ministry of Agriculture, Beijing 100081
  • Received:2014-03-31 Revised:2014-05-27 Online:2014-09-16 Published:2014-09-16

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0.22 µm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100 μg·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10.0 μg·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170 μg·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10 μg·kg-1。与喷雾施药方式相比,土壤穴施方式下阿维菌素在土壤中的残留期更长。【结论】在黄瓜种植中,1%阿维菌素缓释粒剂以推荐剂量3.75 g·m-2采用土壤穴施方式使用是安全的。

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

Abstract: 【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·m-2(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·m-2(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 NaCl, 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 supernatant 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 78%-101% with RSD between 1.9% and 9.4% with spiking at 10 μg·kg-1, 50 μg·kg-1 and 100 μg·kg-1. The limit of quantitation (LOQ) of this method was 10μg·kg-1, which could meet the requirement of max residue limits (MRLs) of abamectin. In degradation dynamics experiments, abamectin was not detected in all degradation plant samples collected from in Beijing and Harbin, which suggested that it is not a systemic pesticide. However, abamectin was detected in all soil samples in degradation experiment. The degradation dynamic equations of abamectin in soil were fitted the first-order reaction dynamic equations, and the half-lives of degradation of abamectin were estimated at 7.9 d and 18.7 d in soil. The residue period of abmectin was longer with hole application compared to that with spray application in soil. Abmectin residue was detected in three soil samples collected from Beijing in 2012 with concentration of 10 μg·kg-1, 30 μg·kg-1 and 170 μg·kg-1, respectively. And similarly, abmectin residues were found only in two soil samples collected from Harbin with concentration of 10 μg·kg-1. 【Conclusion】The abamectin sustained release granules (1%) applied with hole application at 3.75 g·m-2 can be considered safe in cucumber planting.

Key words: abamectin, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), dispersive solid phase extraction, degradation, residue, hole application