Study On The Adsorption And Transferabilty Of Propamidine In Soil And Degradation In Water

The propamidine, which is one of few proprietary property rights in our country, has been obtained country registration (The propamidine registration code is LS20040092, The registration number of 2% Propamidine SL is LS20040130). It was patented in China (The application number is 02114480.X and 200410073073.X).Adsorption, transferability and hydrolysis are important environmental behaviors of pesticides. Assessing the adsorption, transferability and hydrolysis of new pesticides has become an integrated part of studies concerning the environmental safety of pesticide. Because this compound is new and unique, there is no its studies on aspect of environmental behavior in the world. In this paper, adsorption, transferability and hydrolysis were studied. The main results were summarized as follows:1. A method was established for determining Propamidine by ion-pair revered-phase high performance liquid chromatography. A C18 column was used with a mobile phase of V(methanol):V(water) =80:20, 3.0mmol/L SDS .The sample was detected with an ultraviolet detector at 258.7nm. The results showed that the standard deviation was 0.209; the coefficient of variation was 0.109%; the linear correlation was 0.9983.2. Adsorption isotherms of Propamidine in three selected soils were studied by using batch equilibrium method, including optimum ratio of water/soil, the time of reaching adsorption equilibrium, temperature, soil pH and soil organic matter; the transferability of Propamidine in the soils also was studied by soil thin layer chromatography. The result shows that there is strong adsorption ability of Propamidine in three soils. The adsorption isotherms of in three soils all were linear, distribution coefficients(Kd) ranged from25.42mL/g and 33.93mL/g to 40.34mL/g, and the order of soils adsorption of Propamidine followed: Shanxi Yellow soil>He'nan Fluvo-aquic soil >Jiangxi Red soil. According to the analysis of the correlation between Kd and physical and chemical properties of the soils, organic matter content of soils and soil pH were the dependent factor in the adsorption. Free energy of adsorption in soil indicated that the adsorption belonged to physical and chemical reaction. Rf(relative flow) of Propamidine was 0.047. The transferability gradation of Propamidine in the soils wasⅠgrade.3. Effects of temperature, pH and different water types (distilled water, groundwater, Wei river water) on the hydrolysis of Propamidine was studied. The experimental results showed that temperature, pH, natural water had little influence on the hydrolysis rate of Propamidine. The half-lives of Propamidine in distilled water at 25℃was 181.929d.