Studies On Analytical Method Of Famoxadone And Its Fate In Soil

Famoxadone is a new highly active, broad-spectrum fungicide that will be popularized in China soon. Famoxadone can control a few diseases in crops. The researches followed were mainly about the analytical method and behavior of famoxadone in soil.In preface, study advancement of famoxadone, the degradation and mobility of pesticide in soil were briefly introduced and summarized .Residue analytical method of famoxadone in citrus and soil were established in chapter one. The famoxadone fungicide in soil, citrus pulp and peel could be extracted with acetone ,then the extract was re-extracted with ethyl acetate-cyclohexane mixture. After being concentrated by evaporation, the extracts were cleaned up by a column chromatography on florisil. The final residue can be detected by GC—ECD (Ni63 ) with high sensitivity. The average recoveries from untreated control samples fortified with famoxadone at rates of 1.75 mg/kg, 0.175 mg/kg, 0.0175mg/kg ranged from 82.71% to 102.12%, and the coefficient of variation was from1.81% to 9.01%.The lowest detectable concentration of famoxadone in soil ,citrus peel and citrus pulp were 0.01mg/kg, 0.015mg/kg, 0.0025mg/kg respectively. The accuracy, repetition and precision of the method were all good to satisfy the essential rules of pesticide residue determination.Degradation dynamic of famoxadone in soil and citrus were studied. Results showed: (DThe degradation fate of famoxadone in soil and citrus could be described by first-order kinetics equation under the subtropical monsoonal climate of south china. The DT₅0 of famoxadone was 21.73d-23.98d in citrus fruit , 26.46d- 27.51d in citrus peel, 9.68d - 13.95d in soil respectively. The final residue of famoxadone was not detected in citrus pulp, 1.7865 mg/kg - 0.6590 mg/kg in citrus peel, and 0.4088 mg/kg-0.1519mg/kg in citrus fruit at recommended dosage. (DThe DTso of famoxadone in non-sterilized soil was 27.6 times faster than that in sterilized soil, which indicates microorganism was the dominant factor affected the degradation of famoxadone in soil. (3)Environment factors including temperature, field capacity and organic matter content could also affect the degradation of famoxadone in soil. The degradation rate was accelerated obviously with the temperature increasing from 15°C to 40°C, especially from 15°C to 25°C. When the field capacity changed from 50%-100%,the...