中国农业科学 ›› 2015, Vol. 48 ›› Issue (9): 1756-1763.doi: 10.3864/j.issn.0578-1752.2015.09.09

• 植物保护 • 上一篇    下一篇

呋虫胺在有机溶剂和水中的手性稳定性

陈增龙1,陈秀2,董丰收1,刘新刚1,徐军1,郑永权1   

  1. 1中国农业科学院植物保护研究所植物病虫害生物学国家重点实验室,北京100193
    2上海市农业技术推广中心,上海201103
  • 收稿日期:2014-11-04 出版日期:2015-05-01 发布日期:2015-05-01
  • 通讯作者: 郑永权,E-mail:zhengyongquan@ippcaas.cn
  • 作者简介:陈增龙,E-mail:zenglchen@163.com
  • 基金资助:
    国家自然科学基金(31471798)

Chiral Stability of Dinotefuran in Organic Solvents and Water

CHEN Zeng-long1, CHEN Xiu2, DONG Feng-shou1, LIU Xin-gang1, XU Jun1, ZHENG Yong-quan1   

  1. 1State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193
    2
    Shanghai Agriculture Technology Extension and Service Center, Shanghai 201103
  • Received:2014-11-04 Online:2015-05-01 Published:2015-05-01

摘要: 【目的】在人工氙灯光照、室内自然光照和避光培养条件下,探究呋虫胺外消旋体(Rac-呋虫胺)及其对映体(S-呋虫胺和R-呋虫胺)在甲醇、乙醇、异丙醇、乙酸乙酯、乙腈、二氯甲烷、超纯水以及β-环糊精水溶液中的手性稳定性,为大宗用量的手性新烟碱类杀虫剂呋虫胺的准确检测分析、药效和环境安全的正确评价提供依据。【方法】培养周期内分段取样,以直链淀粉-三(3, 5-二甲基苯基氨基甲酸酯)为手性固定相,正己烷/甲醇/乙醇(85/10/5, v/v/v)为流动相,柱温为30℃,流速为1.0 mL?min-1,紫外检测波长为270 nm,进样量为20 µL,高效液相色谱/二极管阵列检测器(HPLC/DAD)进行分离分析,S-呋虫胺和R-呋虫胺的保留时间分别为8.3和9.7 min。外标法定量。【结果】人工氙灯光照、室内自然光照和避光培养条件下,S-呋虫胺和R-呋虫胺在甲醇、乙醇、异丙醇、乙酸乙酯、乙腈、二氯甲烷、超纯水以及β-环糊精水溶液中均不存在相互转化现象;配对样品t-test分析Rac-呋虫胺在每种溶剂中两个对映体的降解残留量,证实无对映体选择性降解。对映体浓度比值(EF值)为0.4746—0.5116。但在人工氙灯光照下,Rac-呋虫胺、S-呋虫胺和R-呋虫胺迅速降解,顺序为二氯甲烷>乙腈>乙酸乙酯≈异丙醇≈乙醇>甲醇>超纯水>β-环糊精水溶液。相比水溶液,呋虫胺在有机溶剂中更容易降解,半衰期分别为3.3—3.6 h和1.2—2.3 h。光解动态符合一级动力学模型,相关系数为0.9550—0.9959。室内自然光照与避光培养条件下,Rac-呋虫胺、S-呋虫胺和R-呋虫胺在二氯甲烷、乙腈、乙酸乙酯、异丙醇、乙醇、甲醇、超纯水和β-环糊精水溶液中无明显降解,实测浓度和相对标准偏差分别为9.5—10.4 mg?L-1,1.0%—3.2%和9.5—10.5 mg?L-1,1.4%—2.8%。【结论】在(25±2)℃人工氙灯光照、室内自然光照和避光条件下,呋虫胺在甲醇、乙醇、异丙醇、乙酸乙酯、乙腈、二氯甲烷、超纯水以及β-环糊精水溶液中手性构型稳定,在此条件下进行定性定量分析、药效和环境安全评价是准确的。

关键词: 呋虫胺, 对映体选择性, 光化学降解, 转化

Abstract: 【Objective】The objective of this study is to investigate the chiral stability of dinotefuran racemate (Rac-dinotefuran) and enantiomers (S-dinotefuran and R-dinotefuran) in methanol, ethanol, isopropanol, ethyl acetate, acetonitrile, dichloromethane, ultrapure water and β-cyclodextrin solution under xenon lamp, natural light, and dark, determine chiral neonicotinoid dinotefuran used extensively in China, and to accurately evaluate its efficacy and environmental safety.【Method】The samples were collected periodically during the whole experimental process. Dinotefuran enantiomers were analyzed by high performance liquid chromatography/diode array detector (HPLC/DAD) with amylose tris-3, 5-dimethylphenylcarbamate as chiral stationary phase and n-hexane/methanol/ethanol (85/10/5,v/v/v) as mobile phase. The ultraviolet detection wavelength of the DAD was identified at 270 nm. The column temperature was set at 30 and the injection volume was 20 µL. The retention times of S-dinotefuran and R-dinotefuran were 8.3 and 9.7 min. The quantification of dinotefuran enantiomers was made by using external standard method.【Result】No transformation was observed between S-dinotefuran and R-dinotefuran in methanol, ethanol, isopropanol, ethyl acetate, acetonitrile, dichloromethane, ultrapure water and β-cyclodextrin solution under xenon lamp, natural light and dark conditions. Dinotefuran did not undergo enantioselective degradation by the student’s paired t-test for the Rac-dinotefuran in all the solvents. The enantiomer fractions (EF) were 0.4746-0.5116. However, Rac-dinotefuran, S>acetonitrile>ethyl acetate≈isopropanol ≈ethanol>methanol>ultrapure water>β-cyclodextrin solution. The degradation of dinotefuran enantiomers in the organic solvents was faster than in the aqueous solutions and the estimated half-lives were 3.3-3.6 h and 1.2-2.3 h, respectively. The photodegradation followed first-order kinetics mode and the correlation coefficients were ranged from 0.9550 to 0.9959. Rac-dinotefuran, S-dinotefuran and R-dinotefuran showed no obvious degradation in dichloromethane, acetonitrile, ethyl acetate, isopropanol, ethanol, methanol, ultrapure water, and β-cyclodextrin solution under natural light and dark during the whole experimental process. The measured concentration and the corresponding relative standard deviation were 9.5-10.4 mg?L-1 and 1.0%-3.2% under natural light, whereas they were 9.5-10.5 mg?L-1 and 1.4%-2.8% under dark. 【Conclusion】Dinotefuran enantiomers were chiral configuration stability in methanol, ethanol, isopropanol, ethyl acetate, acetonitrile, dichloromethane, ultrapure water, and β-cyclodextrin solution under xenon lamp, natural light and dark condition conditions at (25±2)℃. The qualitative and quantitative analysis, efficacy and environmental safety assessment were accurate under these conditions.-dinotefuran and R-dinotefuran were degraded rapidly in the solvents under xenon lamp. The order of the degradation rate was dichloromethane

Key words: dinotefuran, enantioselectivity, photodegradation, transformation