Study Dissipation And Residae Bekavior Of Five Pesticides In Crop And Soil Under Field Application

With the improvement of living conditions, people begin to focus on the quality of the agricultural products especially the problems of pesticide residues have become a hot issue which has attracted great concern of the society. Every year the poisoning incidences caused by pesticide pollution occurred frequently, millions of people’s daily life is influenced by such problems. At present, the qualitative and quantitative analysis technology of pesticide remnants in agricultural products has made great progresses; the methods used to determine pesticide include gas chromatography or high-performance liquid chromatography coupled with various detections, GS-MS analysis, immunoassay, biosensors, and portable pesticide detection kit and so on. The thesis starts from the real situation. To utilize the useful messages provided by chromatograph, the thesis establishes the qualitative and quantitative analysis methods for deterring pesticide remnants in plants.In chapter two and three of this paper, GC analytical method was presented to detect the residues of herbicide acetochlor, atrazine and2,4-d butyl ester in corn, and the degradation law of the three kinds of herbicides in maize plants and soil was also studied. The results showed that within the fixed concentration, the standard curves of acetochlor, atrazine and2,4-d butyl ester were good and related coefficients were r=0.999, r=0.992, r=0.998respectively. The LOQs were5μg/kg,10μg/kg and2μg/kg.In addition, the degradation dynamic test results showed that the degradations of acetochlor in the maize plants and the soil in Harbin were in accordance with the first order dynamic equation and the average half-times were5.70days and15.30days respectively. The residue of acetorchlor in the maize plants in Jinan was too low to count half-life. And the average half-times of atrazine in the maize plants and the soil in Harbin were5.98days and15.68days respectively. The residue of acetorchlor in the maize plants in Jinan was also too low to count half-life. While the average half-life of2,4-d butyl ester in the soil in Harbin was29.0days.In chapter four of this paper, GC analytical method was presented to detect the residues of pretilachlor in wheat, and the degradation law of this kind of herbicides in soil and wheat plants was also studied. The results showed that within the fixed concentration, the standard curves of pretilachlor was good and related coefficients was r=0.9998. The LOQ were5μ.g/kg in soil, and5μ.g/kg in wheat, and10μg/kg in wheat plants. The results showed that the degradations of pretilachlor in soil and wheat plants were in accordance with the first order dynamic equation and the average half-times were8.3～14days and1.5～3.1days respectively.In chapter five of this paper, GC analytical method was presented to detect the residues of captan in grapes, and the degradation law of this kind of herbicides in soil and grapes was also studied. The results showed that within the fixed concentration, the standard curves of captan was good and related coefficients was r=0.9998. The LOQ were10μ.g/kg in soil and10μ.g/kg in grapes. The results showed that the degradations of captan in soil and grapes were in accordance with the first order dynamic equation and the average half-times were3.0～6.3days and2.7～5.8days respectively.