An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai （cruciferous vegetable）, chicken, fish, and po...An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai （cruciferous vegetable）, chicken, fish, and pork] was developed using gas chromatography （GC-ECD） and liquid chromatography tandem mass spectrometry （LC-MS/MS）. Samples were extracted using acetone and n-hexane mixed solvent （1：2, v/v） and then purified using solid-phase extraction （SPE） columns. The extracts were analyzed using GC-ECD and LC-MS/MS. The multiple reaction monitoring （MRM） scheme used involved transitions of the precursor ions to selected two product ions in which one pair for identification was m/z 529 → 293 and another pair for quantification was m/z 529 → 249. The detection limits （LODs） of the method were 0.0015 and 0.0006 mg kg^-1, and the quantification limits （LOQs） were 0.005 and 0.002 mg kg^-1 for GC-ECD and LC-MS/MS, respectively. The relative standard deviations （RSDs） of recovery for indoxacarb were lower than 15% in 10 types of agro-products. Ten repetitive determinations of recovery achieved good reproducibility for indoxacarb and the recovery ranged from 72.08 to 113.74%. The proposed procedure was applied to the analysis of several real samples of different origin from Fujian Province, China, and 299 samples were screened for indoxacarb residue, of which 5 positive samples were found.展开更多
A rapid, simple and an efficient method for the determination of indoxacarb in cauliflower and soil samples was developed and validated using QuEChERS technique (Quick, Easy, Cheap, Effective, Rugged and Safe). Recove...A rapid, simple and an efficient method for the determination of indoxacarb in cauliflower and soil samples was developed and validated using QuEChERS technique (Quick, Easy, Cheap, Effective, Rugged and Safe). Recoveries at four different spiking concentrations of 0.01, 0.05, 0.1 and 0.2 mg kg–1 ranged from 87 to 96% were achieved with good repeatability and RSD of 1% - 6%. The average initial deposits of 0.23 and 0.45 mg kg–1 were observed after last application of indoxacarb @ 52.2 and 104.4 g. a.i. ha–1 at recommended and double the recommended dosages, respectively. The residues in cauliflower dissipated below its LOQ of 0.01 mg kg–1 after 7 days and its half-life periods were observed to be 1.12 and 1.31 days, respectively, at single and double the dosages. Keeping in view 80 g consumption of cauliflower curds per day for a 55 kg person, theoretical maximum residue contribution (TMRC) of indoxacarb when calculated from maximum residues observed on 0 day samples at recommended and double the recommended dosages, respectively, were found to be 20.8 and 36.8 μg in comparison to its acceptable daily intake (ADI) of 550 μg, which is quite safe.展开更多
The biological half-life and final residue levels of indoxacarb and pyridalyl were determined in cauliflower over a 10-day cultivation period following applications of a standard (100 g a.i.ha–1 and 200 g a.i.·h...The biological half-life and final residue levels of indoxacarb and pyridalyl were determined in cauliflower over a 10-day cultivation period following applications of a standard (100 g a.i.ha–1 and 200 g a.i.·ha–1, respectively) and double dose (200 g a.i.·ha–1 and 400 g a.i.·ha–1, respectively). The residue levels were analyzed by gas chromatography with recovery ranging from 92.1% to 109.7%. The biological half-lives of indoxacarb and pyridalyl were 6.33 and 7.74 days for the standard dose, and 6.26 and 7.44 days for the double dose, respectively. The initial and persisting concentrations of indoxacarb and pyridalyl were all below the Korean maximum residue limits for broccoli of 1.0 mgkg–1 and 3.0 mgkg–1, respectively.展开更多
[Objective]The paper was to study a synthetic method suitable for industrial production of intermediate N-Chloroformyl-N-[4-(trifluoromethoxy)phenyl]methyl carbamate of indoxacarb.[Method]Using 4-trifluoromethoxy anil...[Objective]The paper was to study a synthetic method suitable for industrial production of intermediate N-Chloroformyl-N-[4-(trifluoromethoxy)phenyl]methyl carbamate of indoxacarb.[Method]Using 4-trifluoromethoxy aniline as the starting material,[4-(trifluoromethoxy)phenyl]carbamate was synthesized by homogeneous formylation method without acid-binding agent.Subsequently,it was reacted with sodium methoxide/potassium methoxide by reactive distillation to obtain[4-(trifluoromethoxy)phenyl]carbamate ammonium sodium/potassium,then directly reacted with triphosgene to obtain crude products of N-carbonochloridoyl-N-[4-(trifluoromethoxy)phenyl]carbamate;finally,competing product was obtained by recrystallization.[Result]The intermediate N-chloroformyl-N-[4-(trifluoromethoxy)phenyl]carbamate was synthesized by the method.The content of products was higher than 98%.The yield of product reached above 96%(calculated by 4-trifluoromethoxy aniline).[Conclusion]The method used for the synthesis of intermediate N-chloroformyl-N-[4-(trifluoromethoxy)phenyl]methyl carbamate was simple,with less three wastes,higher safety and lower cost.展开更多
草地贪夜蛾Spodoptera frugiperda (J. E. Smith)是一种杂食性害虫,原产于美洲热带和亚热带地区,于2019年1月在中国云南省首次被发现后,已迅速向广西、贵州、广东及湖南等地蔓延。草地贪夜蛾寄主广泛,常用化学防治药剂为有机磷类、氨基...草地贪夜蛾Spodoptera frugiperda (J. E. Smith)是一种杂食性害虫,原产于美洲热带和亚热带地区,于2019年1月在中国云南省首次被发现后,已迅速向广西、贵州、广东及湖南等地蔓延。草地贪夜蛾寄主广泛,常用化学防治药剂为有机磷类、氨基甲酸酯类和拟除虫菊酯类,田间抗性监测数据显示,其对上述3类常用药剂已达中至高等抗性水平。此外,已有研究证明氯菊酯抗性草地贪夜蛾对二嗪类杀虫剂茚虫威无交互抗性;同时已有关于草地贪夜蛾对氟苯虫酰胺和氯虫苯甲酰胺田间和室内抗性的报道,表明其对上述2种药剂存在极高的交互抗性风险。草地贪夜蛾的抗药性机理主要涉及表皮穿透性降低、解毒作用增强和靶标敏感性下降等几方面,其中代谢解毒作用增强和靶标敏感性下降是导致草地贪夜蛾对杀虫剂产生抗性的主要机制。文章综述了草地贪夜蛾对传统杀虫剂和新型作用机制杀虫剂的抗性现状及抗性机理等方面的研究进展,以期对当前中国的草地贪夜蛾田间防治及抗性研究和防控提供参考。展开更多
基金grants from Fujian Pro- vincial Department of Science and Technology (2006F3002)Xiamen Science and Technology Bureau (3502Z20072003)China Postdoctoral Programme (20060390291)
文摘An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai （cruciferous vegetable）, chicken, fish, and pork] was developed using gas chromatography （GC-ECD） and liquid chromatography tandem mass spectrometry （LC-MS/MS）. Samples were extracted using acetone and n-hexane mixed solvent （1：2, v/v） and then purified using solid-phase extraction （SPE） columns. The extracts were analyzed using GC-ECD and LC-MS/MS. The multiple reaction monitoring （MRM） scheme used involved transitions of the precursor ions to selected two product ions in which one pair for identification was m/z 529 → 293 and another pair for quantification was m/z 529 → 249. The detection limits （LODs） of the method were 0.0015 and 0.0006 mg kg^-1, and the quantification limits （LOQs） were 0.005 and 0.002 mg kg^-1 for GC-ECD and LC-MS/MS, respectively. The relative standard deviations （RSDs） of recovery for indoxacarb were lower than 15% in 10 types of agro-products. Ten repetitive determinations of recovery achieved good reproducibility for indoxacarb and the recovery ranged from 72.08 to 113.74%. The proposed procedure was applied to the analysis of several real samples of different origin from Fujian Province, China, and 299 samples were screened for indoxacarb residue, of which 5 positive samples were found.
文摘A rapid, simple and an efficient method for the determination of indoxacarb in cauliflower and soil samples was developed and validated using QuEChERS technique (Quick, Easy, Cheap, Effective, Rugged and Safe). Recoveries at four different spiking concentrations of 0.01, 0.05, 0.1 and 0.2 mg kg–1 ranged from 87 to 96% were achieved with good repeatability and RSD of 1% - 6%. The average initial deposits of 0.23 and 0.45 mg kg–1 were observed after last application of indoxacarb @ 52.2 and 104.4 g. a.i. ha–1 at recommended and double the recommended dosages, respectively. The residues in cauliflower dissipated below its LOQ of 0.01 mg kg–1 after 7 days and its half-life periods were observed to be 1.12 and 1.31 days, respectively, at single and double the dosages. Keeping in view 80 g consumption of cauliflower curds per day for a 55 kg person, theoretical maximum residue contribution (TMRC) of indoxacarb when calculated from maximum residues observed on 0 day samples at recommended and double the recommended dosages, respectively, were found to be 20.8 and 36.8 μg in comparison to its acceptable daily intake (ADI) of 550 μg, which is quite safe.
文摘The biological half-life and final residue levels of indoxacarb and pyridalyl were determined in cauliflower over a 10-day cultivation period following applications of a standard (100 g a.i.ha–1 and 200 g a.i.·ha–1, respectively) and double dose (200 g a.i.·ha–1 and 400 g a.i.·ha–1, respectively). The residue levels were analyzed by gas chromatography with recovery ranging from 92.1% to 109.7%. The biological half-lives of indoxacarb and pyridalyl were 6.33 and 7.74 days for the standard dose, and 6.26 and 7.44 days for the double dose, respectively. The initial and persisting concentrations of indoxacarb and pyridalyl were all below the Korean maximum residue limits for broccoli of 1.0 mgkg–1 and 3.0 mgkg–1, respectively.
文摘[Objective]The paper was to study a synthetic method suitable for industrial production of intermediate N-Chloroformyl-N-[4-(trifluoromethoxy)phenyl]methyl carbamate of indoxacarb.[Method]Using 4-trifluoromethoxy aniline as the starting material,[4-(trifluoromethoxy)phenyl]carbamate was synthesized by homogeneous formylation method without acid-binding agent.Subsequently,it was reacted with sodium methoxide/potassium methoxide by reactive distillation to obtain[4-(trifluoromethoxy)phenyl]carbamate ammonium sodium/potassium,then directly reacted with triphosgene to obtain crude products of N-carbonochloridoyl-N-[4-(trifluoromethoxy)phenyl]carbamate;finally,competing product was obtained by recrystallization.[Result]The intermediate N-chloroformyl-N-[4-(trifluoromethoxy)phenyl]carbamate was synthesized by the method.The content of products was higher than 98%.The yield of product reached above 96%(calculated by 4-trifluoromethoxy aniline).[Conclusion]The method used for the synthesis of intermediate N-chloroformyl-N-[4-(trifluoromethoxy)phenyl]methyl carbamate was simple,with less three wastes,higher safety and lower cost.
文摘草地贪夜蛾Spodoptera frugiperda (J. E. Smith)是一种杂食性害虫,原产于美洲热带和亚热带地区,于2019年1月在中国云南省首次被发现后,已迅速向广西、贵州、广东及湖南等地蔓延。草地贪夜蛾寄主广泛,常用化学防治药剂为有机磷类、氨基甲酸酯类和拟除虫菊酯类,田间抗性监测数据显示,其对上述3类常用药剂已达中至高等抗性水平。此外,已有研究证明氯菊酯抗性草地贪夜蛾对二嗪类杀虫剂茚虫威无交互抗性;同时已有关于草地贪夜蛾对氟苯虫酰胺和氯虫苯甲酰胺田间和室内抗性的报道,表明其对上述2种药剂存在极高的交互抗性风险。草地贪夜蛾的抗药性机理主要涉及表皮穿透性降低、解毒作用增强和靶标敏感性下降等几方面,其中代谢解毒作用增强和靶标敏感性下降是导致草地贪夜蛾对杀虫剂产生抗性的主要机制。文章综述了草地贪夜蛾对传统杀虫剂和新型作用机制杀虫剂的抗性现状及抗性机理等方面的研究进展,以期对当前中国的草地贪夜蛾田间防治及抗性研究和防控提供参考。
