In practice, pesticides are usually applied simultaneously or one after another for crop protection, and this type of pesticide application often leads to a combined contamination of pesticide residues in the soil env...In practice, pesticides are usually applied simultaneously or one after another for crop protection, and this type of pesticide application often leads to a combined contamination of pesticide residues in the soil environment. A laboratory study was conducted to investigate the influence of chlorothalonil on chlorpyrifos degradation and its effects on soil bacterial, fungal, and actinomycete populations. Under the experimental conditions here, the half-lives of chlorpyrifos alone, and in combination with chlorothalonil, at the recommended and double dosages, were measured to be 3.24, 2.77, and 2.63 d, respectively. Chlorpyrifos degradation was not significantly altered by its combination with chlorothalonil. However, the inhibitory effect of chlorpyrifos on soil microorganisms was increased by its combination with chlorothalonil, and the increase was related to the levels of chlorothalonil added. Compared to those in the controls, the populations of bacteria, fungi, and actinomycetes were significantly reduced by 44.1%, 61.1%, and 72.8%, respectively, on the first day after treatment （DAT） by chlorpyrifos alone. With the addition of chlorothalonil, the inhibition was increased to 55.2%, 79.3%, and 85,8% at the recommended dosage, and 86.0%, 94.1%, and 90.8% at the double dosage, at one DAT, respectively. The results suggested that combined effects should be taken into account to assess the actual impacts of pesticide applications.展开更多
The effects of chlorothalonil and carbendazim on nitrification and denitrification in six soils in upland and rice paddy environments were investigated. Laboratory aerobic （60% water holding capacity） and anaerobic ...The effects of chlorothalonil and carbendazim on nitrification and denitrification in six soils in upland and rice paddy environments were investigated. Laboratory aerobic （60% water holding capacity） and anaerobic （flooded） conditions were studied at 25℃ and fungicide addition rates of 5.5 mg/kg A. I. （field rate, FR）, 20 times （20FR） and 40 times （40FR） field rate, respectively. The results indicated that chlorothalonil at the field rate had a slight inhibitory effect on one soil only, and that soil did not nitrify much in the first place. But chlorothalonil at higher rates inhibited nitrification significantly in all soils. For soils JXP and JXU with a pH of less than 5.0, chlorothalonil almost completely stopped their nitrification at 20FR and 40FR during the whole 14 d incubation period. For soils HNP and HNU with a pH of greater than 8.0, chlorothalonil also significantly inhibit nitrification at 20FR and 40FR （p 〈 0.05）. However, NH4＋ that was added to the soil was also almost completely nitrified by the end of the incubation period in these two soils. The effects of chlorothalonil at 20FR and 40FR on the nitrification of JSP and JSU soils, with a pH of 5.4 and 7.2, respectively, were intermediate between the other soil types. Chlorothalonil had no effect on denitrification at the field rate and had little effect at the higher rates of application in some soils. Carbendazim had essentially no effect on nitrification and denitrification in soils assessed.展开更多
Twenty-six novel benzoylphenylurea chitin inhibitor derivatives have been synthesized in over 30~50% yield from chlorothalonil 1 via sequential fluorine exchange, aminolysis, hydrolysis, decarboxylation and acylation ...Twenty-six novel benzoylphenylurea chitin inhibitor derivatives have been synthesized in over 30~50% yield from chlorothalonil 1 via sequential fluorine exchange, aminolysis, hydrolysis, decarboxylation and acylation reactions.展开更多
Six novel benzoylphenylurea chitin inhibitor derivatives were synthesized in the yields of 30%_50% from the readily available starting material chlorothalonil 1 viasequential fluorine exchange, aminolysis, hydrolysis ...Six novel benzoylphenylurea chitin inhibitor derivatives were synthesized in the yields of 30%_50% from the readily available starting material chlorothalonil 1 viasequential fluorine exchange, aminolysis, hydrolysis and acylation reactions.展开更多
[Objectives] This study was conducted to explore the dissipation dynamics of chlorothalonil （2,4,5,6-tetrachloroisophthalonitrile） in scallion.[Methods] The level of residue and the dissipation of chlorothalonil and...[Objectives] This study was conducted to explore the dissipation dynamics of chlorothalonil （2,4,5,6-tetrachloroisophthalonitrile） in scallion.[Methods] The level of residue and the dissipation of chlorothalonil and its main metabolite 4-hydroxy-2,5,6-trichloroisophthalonitrile in scallion in Beijing and Jiangsu experimental bases were determined via acetonitrile extraction and ultra-performance liquid chromatography coupled with ultraviolet detection （UPLC-UV）.[Results] The dissipation of chlorothalonil in scallion followed the first-order kinetic model and the half-life of chlorothalonil in scallion was 3.5-4.1 d. The final residue of chlorothalonil in scallion decreased over time after the last application. After chlorothalonil was applied at 1 050 or 1 575 g a.i./hm 2 3 or 4 times, the maximum residue level of chlorothalonil was 1.48, 1.21, 0.72 and 0.45 mg/kg 5, 7, 10 and 14 d after the last application, while that of its 4-hydroxy metabolite was 0.25, 0.19, 0.13 and 0.09 mg/kg, respectively.[Conclusions] The results may provide experimental evidence for evaluating the safety of the use of chlorothalonil in scallion.展开更多
An effective method was established to determine the content of residual chlorothalonil in textiles by gas chromatography/mass spectrometry-selected ion monitoring coupled with ultrasonic extraction technique. Residua...An effective method was established to determine the content of residual chlorothalonil in textiles by gas chromatography/mass spectrometry-selected ion monitoring coupled with ultrasonic extraction technique. Residual chlorothalonil in textiles was ultrasonically extracted using ethyl acetate as the extraction solvent. The extract was condensed and analyzed by gas chromatography/mass spectrometry in selected ion monitoring mode (GC/MS-SIM). The concentration of chlorothalonil was calibrated by the external standard method. Good linearity existed between the peak area and the mass concentration of chlorothalonil in the mass concentration range from 0.2 μg/mL to 42.8 μg/mL. The equation was A = 95,399ρ ? 50,848, with a correlation coefficient of 0.9999. The limit of detection was 0.1 mg/kg for chlorothalonil. The blank samples were spiked at three concentration levels, and the spiked average recoveries changed from 81.9% to 95.4% while the relative standard deviation (RSD) changed from 1.8% to 5.2%. The proposed method was simple, rapid, sensitive and the limit of detection could meet the limit requirements of relevant regulations. Commercially available textiles were measured by this method, and chlorothalonil at different concentration levels was detected in some samples.展开更多
[Objective]The paper was to develop a novel fungicide with high efficacy and low toxicity.[Method]Chlorothalonil was used as the parent structure,and its 4-position substituent was converted to amino group.Totally 12 ...[Objective]The paper was to develop a novel fungicide with high efficacy and low toxicity.[Method]Chlorothalonil was used as the parent structure,and its 4-position substituent was converted to amino group.Totally 12 amide compounds not reported in the literature were designed and synthesized.Their structures were conformed by 1H NMR.[Result]The preliminary bioassay test showed that compounds JTCN-01,JTCN-05 and JTCN-07 had good control effect on corn rust at the concentration of 200 mg/L,and the control effect of compound JTCN-05 reached 95%.[Conclusion]Some chlorothalonil derivatives had the potential for further development.展开更多
Factors on degradation of chlorothalonil(CLT) in water by high frequency ultrasonic irradiation were investigated.The effects of initial concentration of chlorothalonil,dosages of tertiary butyl alcohol,humic acid and...Factors on degradation of chlorothalonil(CLT) in water by high frequency ultrasonic irradiation were investigated.The effects of initial concentration of chlorothalonil,dosages of tertiary butyl alcohol,humic acid and initial pH value on degradation of chlorothalonil,as well as the reaction mechanism were studied.The results reveal that chlorothalonil could be effectively degradated by ultrasonic irradiation.The reaction constant value kapp decreased from 0.014 1 to 0.010 2 min-1 with the initial concentration increasing from 50 to 400 μg/L during 180 min irradiation.Tertiary butyl alcohol had negative effect on chlorothalonil degradation,while lower concentration of humic acid promoted the sonolysis,and kapp declined with the further concentration increasing.The kapp varied little when the pH value ranged from 3.10 to 10.28.It may be concluded that mechanical and pyrolysis process played main roles on the degradation of chlorothalonil in ultrasonic irradiation rather than ·OH attack.The electrical energy per order(EEo) values for sonolysis degradation of CLT were also calculated to evaluate the cost of the process.展开更多
文摘In practice, pesticides are usually applied simultaneously or one after another for crop protection, and this type of pesticide application often leads to a combined contamination of pesticide residues in the soil environment. A laboratory study was conducted to investigate the influence of chlorothalonil on chlorpyrifos degradation and its effects on soil bacterial, fungal, and actinomycete populations. Under the experimental conditions here, the half-lives of chlorpyrifos alone, and in combination with chlorothalonil, at the recommended and double dosages, were measured to be 3.24, 2.77, and 2.63 d, respectively. Chlorpyrifos degradation was not significantly altered by its combination with chlorothalonil. However, the inhibitory effect of chlorpyrifos on soil microorganisms was increased by its combination with chlorothalonil, and the increase was related to the levels of chlorothalonil added. Compared to those in the controls, the populations of bacteria, fungi, and actinomycetes were significantly reduced by 44.1%, 61.1%, and 72.8%, respectively, on the first day after treatment （DAT） by chlorpyrifos alone. With the addition of chlorothalonil, the inhibition was increased to 55.2%, 79.3%, and 85,8% at the recommended dosage, and 86.0%, 94.1%, and 90.8% at the double dosage, at one DAT, respectively. The results suggested that combined effects should be taken into account to assess the actual impacts of pesticide applications.
基金supported by the National Natural Science Foundation of China (No. 40621001)
文摘The effects of chlorothalonil and carbendazim on nitrification and denitrification in six soils in upland and rice paddy environments were investigated. Laboratory aerobic （60% water holding capacity） and anaerobic （flooded） conditions were studied at 25℃ and fungicide addition rates of 5.5 mg/kg A. I. （field rate, FR）, 20 times （20FR） and 40 times （40FR） field rate, respectively. The results indicated that chlorothalonil at the field rate had a slight inhibitory effect on one soil only, and that soil did not nitrify much in the first place. But chlorothalonil at higher rates inhibited nitrification significantly in all soils. For soils JXP and JXU with a pH of less than 5.0, chlorothalonil almost completely stopped their nitrification at 20FR and 40FR during the whole 14 d incubation period. For soils HNP and HNU with a pH of greater than 8.0, chlorothalonil also significantly inhibit nitrification at 20FR and 40FR （p 〈 0.05）. However, NH4＋ that was added to the soil was also almost completely nitrified by the end of the incubation period in these two soils. The effects of chlorothalonil at 20FR and 40FR on the nitrification of JSP and JSU soils, with a pH of 5.4 and 7.2, respectively, were intermediate between the other soil types. Chlorothalonil had no effect on denitrification at the field rate and had little effect at the higher rates of application in some soils. Carbendazim had essentially no effect on nitrification and denitrification in soils assessed.
基金support of the Natural Science Foundation of Yunnan Province(1999B0005M)the Open Foundation of State Key Laboratory of Elemento-Organic Chemistry,Nankai University
文摘Twenty-six novel benzoylphenylurea chitin inhibitor derivatives have been synthesized in over 30~50% yield from chlorothalonil 1 via sequential fluorine exchange, aminolysis, hydrolysis, decarboxylation and acylation reactions.
基金Supported by the Natural Science Foundation of Yunnan Province(No.99B0 0 0 5 M) and the Open Foundation of StateKey L aboratory of Elemento- Organic Chemistry,Nankai University,P.R.China
文摘Six novel benzoylphenylurea chitin inhibitor derivatives were synthesized in the yields of 30%_50% from the readily available starting material chlorothalonil 1 viasequential fluorine exchange, aminolysis, hydrolysis and acylation reactions.
文摘[Objectives] This study was conducted to explore the dissipation dynamics of chlorothalonil （2,4,5,6-tetrachloroisophthalonitrile） in scallion.[Methods] The level of residue and the dissipation of chlorothalonil and its main metabolite 4-hydroxy-2,5,6-trichloroisophthalonitrile in scallion in Beijing and Jiangsu experimental bases were determined via acetonitrile extraction and ultra-performance liquid chromatography coupled with ultraviolet detection （UPLC-UV）.[Results] The dissipation of chlorothalonil in scallion followed the first-order kinetic model and the half-life of chlorothalonil in scallion was 3.5-4.1 d. The final residue of chlorothalonil in scallion decreased over time after the last application. After chlorothalonil was applied at 1 050 or 1 575 g a.i./hm 2 3 or 4 times, the maximum residue level of chlorothalonil was 1.48, 1.21, 0.72 and 0.45 mg/kg 5, 7, 10 and 14 d after the last application, while that of its 4-hydroxy metabolite was 0.25, 0.19, 0.13 and 0.09 mg/kg, respectively.[Conclusions] The results may provide experimental evidence for evaluating the safety of the use of chlorothalonil in scallion.
文摘An effective method was established to determine the content of residual chlorothalonil in textiles by gas chromatography/mass spectrometry-selected ion monitoring coupled with ultrasonic extraction technique. Residual chlorothalonil in textiles was ultrasonically extracted using ethyl acetate as the extraction solvent. The extract was condensed and analyzed by gas chromatography/mass spectrometry in selected ion monitoring mode (GC/MS-SIM). The concentration of chlorothalonil was calibrated by the external standard method. Good linearity existed between the peak area and the mass concentration of chlorothalonil in the mass concentration range from 0.2 μg/mL to 42.8 μg/mL. The equation was A = 95,399ρ ? 50,848, with a correlation coefficient of 0.9999. The limit of detection was 0.1 mg/kg for chlorothalonil. The blank samples were spiked at three concentration levels, and the spiked average recoveries changed from 81.9% to 95.4% while the relative standard deviation (RSD) changed from 1.8% to 5.2%. The proposed method was simple, rapid, sensitive and the limit of detection could meet the limit requirements of relevant regulations. Commercially available textiles were measured by this method, and chlorothalonil at different concentration levels was detected in some samples.
基金Supported by Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences(CXGC2018E19).
文摘[Objective]The paper was to develop a novel fungicide with high efficacy and low toxicity.[Method]Chlorothalonil was used as the parent structure,and its 4-position substituent was converted to amino group.Totally 12 amide compounds not reported in the literature were designed and synthesized.Their structures were conformed by 1H NMR.[Result]The preliminary bioassay test showed that compounds JTCN-01,JTCN-05 and JTCN-07 had good control effect on corn rust at the concentration of 200 mg/L,and the control effect of compound JTCN-05 reached 95%.[Conclusion]Some chlorothalonil derivatives had the potential for further development.
基金Project(2008ZX07421-002) supported by the National Major Project of Science & Technology Ministry of ChinaProject(2008AA06A412) supported by the National High Technology Research and Development Program of ChinaProject(20009-K7-4) supported by the Research and Development of Ministry of Housing and Urban-Rural Development of China
文摘Factors on degradation of chlorothalonil(CLT) in water by high frequency ultrasonic irradiation were investigated.The effects of initial concentration of chlorothalonil,dosages of tertiary butyl alcohol,humic acid and initial pH value on degradation of chlorothalonil,as well as the reaction mechanism were studied.The results reveal that chlorothalonil could be effectively degradated by ultrasonic irradiation.The reaction constant value kapp decreased from 0.014 1 to 0.010 2 min-1 with the initial concentration increasing from 50 to 400 μg/L during 180 min irradiation.Tertiary butyl alcohol had negative effect on chlorothalonil degradation,while lower concentration of humic acid promoted the sonolysis,and kapp declined with the further concentration increasing.The kapp varied little when the pH value ranged from 3.10 to 10.28.It may be concluded that mechanical and pyrolysis process played main roles on the degradation of chlorothalonil in ultrasonic irradiation rather than ·OH attack.The electrical energy per order(EEo) values for sonolysis degradation of CLT were also calculated to evaluate the cost of the process.
