Studies On Residue Analysis Of Imibenconazole In Grape Orchards And Its Digestion In Aquatic Environment

Imibenconazole is being popularized to use all over the world today,but very little information is available about residue analysis of imibenconazole in grape orchards and its digestion in aquatic environment.In order to comprehensively evaluate environmental security of imibenconazole and for its reasonably application and ecological environmental restoration,the environmental behavior that include the residue analysis of imibenconazole in grape orchards and digestion in aquatic environment were studied,the influence factors were also referred to.The main conclusion obtained were listed as follows.Chapter one was introduction,in which the basic concepts,theories and current advances were reviewed briefly on pesticides,pesticide residues,hydrolysis and simulation experiments on biodegradation to aquatic of pesticides.In addition, research advance of imibenconazole was summarized concisely.The contents and significances of this research was also included in this chapter.In the chapter two the residue of imibenconazole in grape orchards was studied.The results showed that:(1)A series of experiments were studied for establishing extraction method and clean-up method in preceding process.Identified acetone as the extract,dichloromethane and 5%sodium chloride solution as the elution liquid,florisil as the sorbent were determined finally.(2)The chromatographic condition of imibenconazole were:Column:quartz capillary(30 m×0.25 mm×0.25μm);detector:ECD;column temperature:270℃;inlet temperature:300℃;detector temperature:300℃;N₂:3.5mL/min;makeup:55 mL/min;(3)The results showed that the average recoveries of imibenconazole ranged from 82.72%to 92.18%,and the coefficient of variation was from 5.72%to 7.19%in grape;the average recoveries of imibenconazole ranged from 87.16%to 92.61%,and the coefficient of variation was from 4.61%to 6.94%in soil;the lowest detection of imibenconazole were 0.03mg/kg in grape and 0.02mg/kg in soil.(4) The degradation of imibenconazole in grape and soil were accordance with the first-order dynamic eqution C_t=C₀e^-kt;the half-life of imibenconazole were 12.8,12.74,11.9d and 10.65d in grape,the half-life of imibenconazole were 12.5,12.3,15.6d and 13.6d in soil.(5)Imibenconazole was applied under recommended dose,the residues of its were lower than MRL in grape and soil.Chapter three was the chemistry degradation of imibenconazole in aquatic environment.Results were observed as follow:(1)Hydrolysis of imibenonazole in the buffer solutions of pH4,5,6,7,8,9,10 can be described by the first-order kinetics equation,and its hydrolysis half life in the buffer solutions was 1.73,5.91,22.95, 21.20,18.89,16.85d and 11.55d,respectively,suggesting that imibenconazole was stable in basic water and its hydrolysis easily took place in acid water and alkaline water.(2)The higher temperature was helpful for the hydrolysis process.When the pH value was 5,7 and 9,the activation energy of hydrolysis for imibenconazole was 47.74, 56.18 and 53.30kJ/mol,respectively.When the pH value was 7,the temperature coefficient was 1.9.In chapter four,the simulation experiments on biodegradation of imibenconazole in natural water was optimized.The results showed that imibenconazole degraded slowly in with and without sterilization rivers and ponds,their half-lives were 7.5d and 9.2d,in without sterilization rivers and ponds it degraded slightly faster,their half-lives were7.1d and 6.1d,water added natural sediment degraded most rapidly, their half-lives were 2.5d and 1.9d.In the last chapter,a summary was done on the research results,and meanwhile the innovation of the research and the projects that need to be further studied were suggested.