Rearch On Residues And Dissipation Dynamics Of Epoxiconazole In Rice Field

This paper choose epoxiconazole as the research object,systematically studied the degradation dynamic and final residue of epoxiconazole after fertilization in paddy fields within 2014 to 2015.The main results were as follows:Determine the gas chromatography equipped with electron capture detector(GC-ECD)analysis epoxiconazole of testing conditions,the limit of detection(LOD)was 1.0×10-11g,and the limit of quantification(LOQ)of the method was 0.025 mg/L for rice,0.02 mg/kg for paddy water,soil,plant and rice husk.The pretreatment use acetonitrile extraction,C18 and Carb as the dispersant,and the detection by GC-ECD were carried out.The recoveries of epoxiconazole in different matrix of rice field were 82.75%～106.0%,The standard deviation(RSD)was between 2.2%to 8.5%,which was in accordance with the pesticide residue test standard.From 2014 to 2015,the results of dissipation dynamic test showed that the rales consistent with first order kinetics equation,40%epoxiconazole of wettable powder in rice field water and plant dissolve quickly,and the half-life of epoxiconazole was 2.6-12.6 days in plant,2.0-2.2 days in paddy water,respectively.And the degradation of epoxiconazole was more easily.The results of final residue test in 2014 to 2015 showed that the residues of 96 and 144 g.a.i/ha of 40%epoxiconazole were 2 to 3 times,and the residue in brown rice was 0 799 mg/kg at the interval of 15 days and 20 days.In order to ensure the safety of food,it is suggested that 40%epoxiconazole SC should be used to prevent and control rice false smut.The maximum dosage is 240 g/ha(active ingredient 96 g.a.i/ha)and the maximum interval is 20 days.