The Establishment Of The Detection Method Of Vanisulfane Residue And Its Application In The Study Of Soil Degradation

China is a large agricultural producer and a country with extremely high pesticide usage.Although the use of pesticides has ensured the output of agricultural products,problems related to pesticide pollution have also arisen.To solve this problem,the first is to increase research and development efforts to develop new pesticides with high efficiency,low toxicity and low residual performance.The second is to optimize the rapid detection technology of pesticides and carry out research on pesticide environmental behavior.Plant mutagen as a new type of dithioacetal plant mutagenesis resistance is to prevent crops from secreting substances that can resist pests and diseases.As a kind of plant mutagen,Vanisulfane has a significant preventive effect on tomato chlorosis and other plant diseases,has the characteristics of high efficiency and low toxicity,have higher research prospects and research value.in this subject,Vanisulfane used as the research object,and a method for detection od Vanisulfane in soil was established,and the Vanisulfane investigated in three kinds of soils(Nanjing yellow brown soil,Northeast black soil,Jiangxi Red soil)under two conditions(aerobic sterilization and aerobic sterilization)soil degradation law,so as to provide a reference basis for the safe use of Vanisulfane its environmental safety evaluation.The main findings are as follows:(1)Established a QuEChERS-high performance liquid chromatography method for the determination of VanisulfaneThe method has a good linear relationship with the peak area in the concentration range of 0.01-2 mg/L,and the correlation coefficient R2=0.999.The limit of quantification(LOQ)of the method was 0.015mg/L,and the limit of detection(LOD)was 0.0045mg/L.When the spiked concentration of Vanisulfane in the soil was 0.1 mg/kg,0.5 mg/kg,1 mg/kg,the average spiked recovery rate of Vanisulfane in yellow brown soil was 71.99%-93.68%,the relative standard deviation(RSD,n=5)is 2.57%-6.34%;the recovery rate of Vanisulfane in black soil in Northeast China is 83.98%-84.55%,RSD is 3.28%-5.10%;the recovery rate of Vanisulfane in Jiangxi red soil was 75.64%-92.49%,the RSD was 6.43%-10.78%;The recovery rate of this method is up to standard,and the accuracy and precision meet the requirements,so it is suitable for the detection of Vanisulfane.(2)Study on the soil degradation law of VanisulfaneUnder the conditions of indoor simulation,the soil degradation dynamics of Vanisulfane in three kinds of soils before and after sterilization were investigated.The degradation dynamics were consistent with the expression of the first-order kinetic model,and the degradation rate performance under the two conditions Both are yellow brown soil>black soil>red soil.The degradation rate of unsterilized soil is faster than that of sterilized soil.Under non-sterile conditions,the reaction equations of Vanisulfane in Nanjing yellow brown soil,Northeast black soil,and Jiangxi red soil were fitted with Ct=0.9331e-0.219t(R2=0.9634)and Ct=0.6106e-0.192t(R2=0.9145)Ct=0.8197e-0.050t(R2=0.9745),the soil half-lives DT50 are 3.1 7d?3.61d and 13.86d respectively.It can be seen that Vanisulfane is an easily degradable pesticide.The overall digestion rate of the three types of soil was yellow brown soil>black soil>red soil.The digestion rate was mainly affected by microbial and soil enzyme digestion in the early stage(first 7 days),and the half-life rule was consistent with the law of organic matter content,invertase and urease activity.In the later period(after the 7th day),it is mainly affected by the redox and hydrolysis reactions of organic matter,and the half-life rule is consistent with the inorganic matter content rule and the catalase activity rule.In general,the higher the organic matter content and soil enzyme activity,the faster the degradation rate;Under sterilization conditions,the reaction equations fitted by Vanisulfane in the three soils were Ct=0.9094e-0.0883t(R2=0.9617)?Ct=0.8843e-0.0825t(R2=0.9279)?Ct=0.6769e-0.0346t(R2=0.9530),the soil half-lives DT50 are 7.85d?8.40d and 20.03d respectively.The contrast of digestion rate was yellow brown soil>black soil>red soil.The digestion rate of the three soils under sterilization conditions is affected by the redox,hydrolysis,non-inactivated enzymes and microbial activity of non-biologically active organic matter and inorganic matter.Catalase activity is consistent.