Study On The Residues Of Flutriafol And Azoxystrobin In Paddy Samples

40%Azoxystrobin and Flutriafol SC is a new type of bactericide and has special effects to powdery mildew.It is mainly used to prevent and treat disease for crops,such as grain,fruit and vegetable,and their storageand preservation.In order to evaluate the residues in rice planting environmental medium and the stability in storage system,the residue dynamics and terminal residues of 40%azoxystrobin and flutriafol SC in paddy have been studied.The results will provide the scientific basis for the use of 40%azoxystrobin and flutriafol SC in the rice plantations The main results were as follows:1.A gas chromatography(GC)method was.established for the determination of azoxystrobin and flutriafol residue in plant,chaff and rice.Samples were determined with gas chromatography-nitrogen and phosphorus detector(GC-NPD)after extracted with acetonitrile and separated with capillary column.External standard method was adopted for the quantitative analysis.The recoveries of azoxystrobin in plant,chaff and rice were 82.4%-102.6%,93.7%-100.4%and 91.5%-96.5%respectively,with the concentration range of azoxystrobin changed from 0.02 mg/kg to 1.00 mg/kg.The corresponding relative standard deviations(RSDs)were 2.3%-2.9%,1.4%-2.0%and 1.8%-2.8%,respectively.The recoveries of flutriafol in plant,chaff and rice were 92.0%-105.7%,92.2%-94.2%and 94.8%-96.5%respectively,with the concentration range of and flutriafol changed from 0.02 mg/kg to 1.00 mg/kg.The corresponding relative standard deviations RSDs were 1.2%-2.1%,1.5%-2.5%and 0.8%-2.5%,respectively.The limits of detection for az:oxystrobin and flutriafol(S/N=3)in rice were 0.02 mg/kg.The results indicated that the method accords with demands of Ministry of Agriculture for the residue analysis of the pesticide.The method is rapid,simple,and accurate,and has the advantages of low cost and high reliability2.A GC method was established for the determination of azoxystrobin and flutriafol residue in rice planting environmental medium with external standard method for the quantitative analysis.Samples were determined using GC-NPD after extracted with acetonitrile for soil and extracted with dichlormethane for water.The recoveries of azoxystrobin in soil and water were 89.7%-101.7%and 86.1-106.7%,respectively,with the concentration range of azoxystrobin changed from 0.02 mg/kg to 1.00 mg/kg.The corresponding RSDs were 1.6%-2.5%and 1.2%-2.6%,respectively.The recoveries of flutriafol in soil and water were 88.2%-97.3%and 97.1%-106.4%,respectively,with the concentration range of flutriafol changed from 0.02 mg/kg to 1.00 mg/kg.The corresponding RSDs were 1.2%-2.3%and 1.9%-2.6%,respectively.The limit of detections for azoxystrobin and flutriafol(S/N=3)in rice were 0.02 mg/kg.The results indicated that the method accords with demands of Ministry of Agriculture for the residue analysis of pesticide.3.Residues degradation dynamics of 40%azoxystrobin and flutriafol SC in paddy plants,soil and water were studied.The results indicate that the degradation dynamics of 40%azoxystrobin and flutriafol SC in paddy plants,soil and water samples in Hunan,Jangsu and Hebei in 2012 and 2013,respectively,were in accordance with the regression equation of first order dynamic model.The half-life of azoxystrobin and flutriafol in paddy plants,soil and water in Hunan,Jiangsu and Hebei were 4.1 d-39.6 d and 9.7 d-39.6 d,respectively.4.Azoxystrobin and flutriafol have certain residues in paddy plants,chaff and soil after 40%azoxystrobin and flutriafol SC were employed in rice and soil at Hunan,Jiangsu and Hebei.40%azoxystrobin and flutriafol SC were employed twice and thrice with high-dose and low-dose,respectively,on day 30 after the last application,the terminal residues of azoxystrobin and flutriafol in rice were lower than 0.5 mg/kg,which was lower than the maximum residue limit of European Union.