Method Development For Pesticide Residue Aanlysis In Environmental Samples And Study On The Adsorption Behavior Of Pesticide In Soil

As one of the most important contents of agricultural production, pesticide is also the main resources of food and environmental pollution. Since soil is the collecting and distributing center of organic pollutants, research of separation and analysis of pesticide residues, pesticide adsorption and irrigation have been a hotspot in agro-environment science. Hence, establishing analysis method of pesticide residues in soil and water, initiating research on the adsorption behavior of pesticide in soil are significant to the pesticide safty.Three researches have been done in this report as follows.A separation and analysis method for 19 kinds of pesticide residues in respect to 5 different categories in soil was developed in the first part. Pesticides were extracted from soil by using the ultrasonic-assisted extraction, and was cleaned up on a C18 SPE column, then detected by HPLC-UV. Under the optimized conditions, the determination of pesticides in soil by HPLC got good recoveries and RSD conditions, the average recovery rate was: 70.1%-117.9% and RSD was: 0.1%-17.9% in soil; the detection limit was 0.001mg/kg-0.15mg/kg. The method was successfully applied to the analysis of the19 pesticides in soil.In the second part, a method of HPLC was developed and applied for determination of 16 kinds of pesticides residue in relation to 4 categories in water environment. Pesticides were extracted and cleaned up by C18 SPE column. Under the optimized conditions, the determination of pesticides in water environment by HPLC got good recoveries and RSD conditions, the average recovery rate was: 69.8%-112.2% and RSD was: 1.51%-11.64% in soil; the detection limit was 0.004mg/L-0.19mg/L. This method complied with the requirement of pesticide residue analysis.Finally, prometryne and acetochlo as the objects of analysis for researching the adsorption behavior of soil. Comparison among analytical method of GC-FID,GC-MS and HPLC, research of adsorption property based on dynamics and the thermodynamics of the soil for the prometryne and acetochlor, and absorbtion mechanisms between prometryne(acetochlor) and Hum by means of FTIR were proceeded in details . Additionally, prometry(acetochlor) intercalated monmorillonite composites were characterized by the method of XRD in this paper. The result indicated that prometry(acetochlor) adsorbed time of attaining the balance in soil is short(flap to concuss 6 hours to have already neared to adsorb balance); absorbtion amount of prometry and acetochlor were increased with the soil pH value, Adsorption of two pesticides decreased with the anionic surfactant concentrations increasement, and increased with the cationic surfactant concentration decreasement. Adsorption isotherms of prometry and acetochlor conformed to Freundlich equation. The adsprption of prometry and acetochlor in soil could fit well the second- order equation. The thermodynamics of prometryne in soil was a spontaneous pross, adsorption was increased as temperature rose; the thermodynamics of acetochlor in soil was a spontaneous pross, the adsorption was increased as temperature droped. The formulation of H-bonding might contributed to the adsorption in soil ,prometryne and acetochlor could enter the inner layer of some bentonites.