Fenthion and parathion are two representative kinds of organophosphorus pesticides and widely used in agriculture.They are directly or indirectly released into the atmosphere by spraying or volatilization processes.Ho...Fenthion and parathion are two representative kinds of organophosphorus pesticides and widely used in agriculture.They are directly or indirectly released into the atmosphere by spraying or volatilization processes.However,their heterogeneous reactivity toward OH radicals has not yet been well understood.Therefore,this work investigated the heterogeneous kinetics of the OH-initiated degradation of surface-bound fenthion and parathion using a flow reactor.The results showed that OH radicals played an important role in the atmospheric degradation of fenthion and parathion.Their average rate constants were(7.20±0.77)×10^(-12) and(10.40±0.60)×10^(−12) cm^(3)/(mol·sec)at a relative humidity(RH)and temperature of 35% and 20℃,respectively,suggesting that they have relatively short lifetimes in the atmosphere.In addition,a negative RH dependence and a positive temperature dependence of the rate constants were observed.The Arrhenius expressions of fenthion and parathion were k_(2)=(1.34±0.48)×10^(-9) exp[-(1432.59±105.29)/T]and k_(2)=(1.96±1.38)×10^(-9) exp[-(1619.98±222.02)/T],respectively,and their overall activation energy was estimated to be(11.88±0.87)and(13.48±1.83)kJ/mol.The experimental results will update the kinetic data of fenthion and parathion in the atmosphere and be helpful to further understand their atmospheric transportation processes.展开更多
[目的]建立QuEChERS结合UPLC-MS/MS法测定海南豇豆中倍硫磷及其Ⅰ型代谢物的分析方法。[方法]样品经乙腈提取,氯化钠盐析,石墨化炭黑(GCB)和N-丙基乙二胺(PSA)分散固相萃取净化,以Agilent ZORBAX Eclipse Plus C18柱为分离色谱柱,多反...[目的]建立QuEChERS结合UPLC-MS/MS法测定海南豇豆中倍硫磷及其Ⅰ型代谢物的分析方法。[方法]样品经乙腈提取,氯化钠盐析,石墨化炭黑(GCB)和N-丙基乙二胺(PSA)分散固相萃取净化,以Agilent ZORBAX Eclipse Plus C18柱为分离色谱柱,多反应监测(MRM)模式下检测倍硫磷及其Ⅰ型代谢物,定量分析采用溶剂标准曲线法(外标法)。[结果]倍硫磷及其Ⅰ型代谢物在2.0~100.0μg/L质量浓度范围内线性关系良好,相关系数(r)大于0.999;以海南豇豆阴性样品为基质,在2、5、10、50μg/kg 4个质量分数加标水平下,倍硫磷及其Ⅰ型代谢物的平均加标回收率为89.3%~99.3%,相对标准偏差(RSD)为1.2%~7.3%,方法定量限均为2μg/kg。[结论]方法具有简便、高效、准确、廉价等特点,适用于豇豆中倍硫磷及其Ⅰ型代谢物的同时测定。方法的建立可为相关监管部门对豇豆中倍硫磷及其Ⅰ型代谢物农药污染的有效监测提供技术支撑。展开更多
Fenthion is an organothiophosphate insecticide,which is a subset of the organophosphates.The analysis of impurities in the pesticide plays an important role in quality control,making a strong impact on the quality of ...Fenthion is an organothiophosphate insecticide,which is a subset of the organophosphates.The analysis of impurities in the pesticide plays an important role in quality control,making a strong impact on the quality of preparation,crops,non-target organisms,human health and the ecological environment.In this article,fenthion and 7 impurities were separated by GC and HPLC,and identified by using electron impact mass spectrometry(EI MS) and electrospray ionization mass spectrometry(ESI MS) methods.The fragmentation reactions of fenthion were further investigated in order to speculate the fragmentation structures of展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21976098 and 42107260)the Project of Science and Technology Department of Sichuan Province(No.2021YFN0101)+2 种基金the Innovation Leading Talents in Panzhihua,the Opening Project of Key Laboratory of Green Chemistry of Sichuan Institutes of Higher Education(No.LZJ2005)the Cultivation Project of Panzhihua University(No.2020ZD001)the Doctoral Fund of Panzhihua University.
文摘Fenthion and parathion are two representative kinds of organophosphorus pesticides and widely used in agriculture.They are directly or indirectly released into the atmosphere by spraying or volatilization processes.However,their heterogeneous reactivity toward OH radicals has not yet been well understood.Therefore,this work investigated the heterogeneous kinetics of the OH-initiated degradation of surface-bound fenthion and parathion using a flow reactor.The results showed that OH radicals played an important role in the atmospheric degradation of fenthion and parathion.Their average rate constants were(7.20±0.77)×10^(-12) and(10.40±0.60)×10^(−12) cm^(3)/(mol·sec)at a relative humidity(RH)and temperature of 35% and 20℃,respectively,suggesting that they have relatively short lifetimes in the atmosphere.In addition,a negative RH dependence and a positive temperature dependence of the rate constants were observed.The Arrhenius expressions of fenthion and parathion were k_(2)=(1.34±0.48)×10^(-9) exp[-(1432.59±105.29)/T]and k_(2)=(1.96±1.38)×10^(-9) exp[-(1619.98±222.02)/T],respectively,and their overall activation energy was estimated to be(11.88±0.87)and(13.48±1.83)kJ/mol.The experimental results will update the kinetic data of fenthion and parathion in the atmosphere and be helpful to further understand their atmospheric transportation processes.
文摘Fenthion is an organothiophosphate insecticide,which is a subset of the organophosphates.The analysis of impurities in the pesticide plays an important role in quality control,making a strong impact on the quality of preparation,crops,non-target organisms,human health and the ecological environment.In this article,fenthion and 7 impurities were separated by GC and HPLC,and identified by using electron impact mass spectrometry(EI MS) and electrospray ionization mass spectrometry(ESI MS) methods.The fragmentation reactions of fenthion were further investigated in order to speculate the fragmentation structures of
