Commercial suspension emulsion(SE) of(8% chlorfenapyr + 20% clothianidin), as a pre-registered product in China, was firstly investigated under Chinese open-field conditions. A MWCNTs-based QuEChERS method for simulta...Commercial suspension emulsion(SE) of(8% chlorfenapyr + 20% clothianidin), as a pre-registered product in China, was firstly investigated under Chinese open-field conditions. A MWCNTs-based QuEChERS method for simultaneous determination of chlorfenapyr and clothianidin in leek was established and validated through rapid resolution liquid chromatography triples quadrupole tandem mass spectrometry(RRLC-QqQ-MS/MS). Based on this method, the dissipation behaviors, residue distributions and dietary risk probability of these fungicides in leek from two representative locations in China in 2016, which were previously treated with these insecticides at the doses of 420–630 g a.i./ha twice applications, were further investigated for food safety. Dissipation behavior of chlorfenapyr and clothianidin in leek followed first-order kinetics with the half-lives of 2.9–7.2 days, and the highest residues(HR) of these insecticides in leek were below 0.3811 mg/kg and 0.2989 mg/kg, respectively, at the pre-harvest interval(PHI, 7 days). For dietary risk assessments, the risk quotients(RQs) of chlorfenapyr and clothianidin in leek were evaluated by comparing the value of national estimated daily intake(NEDI) with acceptable daily intake(ADI), based on the trials data under good agricultural practices(GAP) conditions. The results indicated that RQs of chlorfenapyr and clothianidin in leek were21.5% and 0.29%, respectively, which exhibited an acceptably low health risk to leek consumption. The current study could not only guide reasonable usage of the formulation, but also facilitate the setting of maximum residue limits(MRLs) of chlorfenapyr and clothianidin in leek for Chinese展开更多
A series of novel neonicotinoid analogues were designed and synthesized by introducing a hydrazide group into clothianidin. Their structures were confirmed by IR, 1H NMR, and HRMS （ESI）. Preliminary bioassay showed ...A series of novel neonicotinoid analogues were designed and synthesized by introducing a hydrazide group into clothianidin. Their structures were confirmed by IR, 1H NMR, and HRMS （ESI）. Preliminary bioassay showed that some compounds, Sb and Sg, exhibited good activity against soybean aphids （Aphis glycines） at 100 mg L ^-1. In addition, molecular docking with receptor was carried out to explain their different activity from clothianidin.展开更多
Application of biochar technology in the remediation of organic contaminated soils has drawn growing interest in recent years.In this study,sorption and degradation of two typical neonicotinoid insecticides,imidaclopr...Application of biochar technology in the remediation of organic contaminated soils has drawn growing interest in recent years.In this study,sorption and degradation of two typical neonicotinoid insecticides,imidacloprid(IMI)and clothianidin(CLO)in Chinese typical paddy soil and red soil amended with six kinds of biochars were investigated.The results showed that surface area(SA),pH,total organic carbon and dissolved organic carbon(DOC)of the two soils all increased after biochar amendment,while H/C decreased.With biochar pyrolyzing temperature(PT)increasing from 300℃ to 700℃,the sorption of the two insecticides on biochar-soil mixtures increased by more than 4.3-fold,due to the increasing SA and decreasing H/C.The acidic pH of the two tested soils also favored the enhanced sorption of the insecticides by removing the ash on biochar.The amendment of low-PT(300℃)biochar promoted the biodegradation of IMI and CLO by 11.3-41.9%via providing more DOC and available N for microorganisms,while inhibiting the chemical degradation.Oppositely,the high-PT(500-700℃)biochars inhibited the biodegradation of the insecticides by decreasing their bioavailability and promoted the chemical degradation by providing mineral active groups,and generating·OH and other free radicals.In addition,soil type also affected the effects of biochar remediation.The highest 60-day degradation extent was achieved for CLO(90.5%)and IMI(81.4%)in paddy soil by adding biochar derived from pig manure at 700℃ PT.In summary,the effect of biochar on the fate of organic contaminants in soil is a comprehensive result involving several processes and a systematic study considering the type and property of biochar and soil is needed to optimize biochar technology.展开更多
基金financially supported by the Natural Science Foundation of Beijing (No. 8162029)National Natural Science Foundation of China (No. 21677009)
文摘Commercial suspension emulsion(SE) of(8% chlorfenapyr + 20% clothianidin), as a pre-registered product in China, was firstly investigated under Chinese open-field conditions. A MWCNTs-based QuEChERS method for simultaneous determination of chlorfenapyr and clothianidin in leek was established and validated through rapid resolution liquid chromatography triples quadrupole tandem mass spectrometry(RRLC-QqQ-MS/MS). Based on this method, the dissipation behaviors, residue distributions and dietary risk probability of these fungicides in leek from two representative locations in China in 2016, which were previously treated with these insecticides at the doses of 420–630 g a.i./ha twice applications, were further investigated for food safety. Dissipation behavior of chlorfenapyr and clothianidin in leek followed first-order kinetics with the half-lives of 2.9–7.2 days, and the highest residues(HR) of these insecticides in leek were below 0.3811 mg/kg and 0.2989 mg/kg, respectively, at the pre-harvest interval(PHI, 7 days). For dietary risk assessments, the risk quotients(RQs) of chlorfenapyr and clothianidin in leek were evaluated by comparing the value of national estimated daily intake(NEDI) with acceptable daily intake(ADI), based on the trials data under good agricultural practices(GAP) conditions. The results indicated that RQs of chlorfenapyr and clothianidin in leek were21.5% and 0.29%, respectively, which exhibited an acceptably low health risk to leek consumption. The current study could not only guide reasonable usage of the formulation, but also facilitate the setting of maximum residue limits(MRLs) of chlorfenapyr and clothianidin in leek for Chinese
基金financially supported by the National Basic Research Program of China(No.2010CB126104)
文摘A series of novel neonicotinoid analogues were designed and synthesized by introducing a hydrazide group into clothianidin. Their structures were confirmed by IR, 1H NMR, and HRMS （ESI）. Preliminary bioassay showed that some compounds, Sb and Sg, exhibited good activity against soybean aphids （Aphis glycines） at 100 mg L ^-1. In addition, molecular docking with receptor was carried out to explain their different activity from clothianidin.
基金supported by the National Key R&D Program of China(2018YFC1802001)the special fund of platform for innovation of Tianjin Science and Technology Commission(19PTZWHZ00040)+1 种基金Science and Technology Major Project of Tianjin(19ZXSZSN00010)and Postdoctoral Science Foundation of China(2019M651018)Ministry of Education of China(111 program,T2017002).
文摘Application of biochar technology in the remediation of organic contaminated soils has drawn growing interest in recent years.In this study,sorption and degradation of two typical neonicotinoid insecticides,imidacloprid(IMI)and clothianidin(CLO)in Chinese typical paddy soil and red soil amended with six kinds of biochars were investigated.The results showed that surface area(SA),pH,total organic carbon and dissolved organic carbon(DOC)of the two soils all increased after biochar amendment,while H/C decreased.With biochar pyrolyzing temperature(PT)increasing from 300℃ to 700℃,the sorption of the two insecticides on biochar-soil mixtures increased by more than 4.3-fold,due to the increasing SA and decreasing H/C.The acidic pH of the two tested soils also favored the enhanced sorption of the insecticides by removing the ash on biochar.The amendment of low-PT(300℃)biochar promoted the biodegradation of IMI and CLO by 11.3-41.9%via providing more DOC and available N for microorganisms,while inhibiting the chemical degradation.Oppositely,the high-PT(500-700℃)biochars inhibited the biodegradation of the insecticides by decreasing their bioavailability and promoted the chemical degradation by providing mineral active groups,and generating·OH and other free radicals.In addition,soil type also affected the effects of biochar remediation.The highest 60-day degradation extent was achieved for CLO(90.5%)and IMI(81.4%)in paddy soil by adding biochar derived from pig manure at 700℃ PT.In summary,the effect of biochar on the fate of organic contaminants in soil is a comprehensive result involving several processes and a systematic study considering the type and property of biochar and soil is needed to optimize biochar technology.
