苯醚甲环唑的水解研究

研究了苯醚甲环唑在水溶液中的水化学降解行为,结果表明:(1)苯醚甲环唑水解作用随溶液pH值的增大而增强,25℃时其在pH5、7和9的缓冲液中的水解半衰期分别为315.07、11.53和1.33d。(2)苯醚甲环唑在水体中的水解速率随温度升高而加快,其在温度为15、25、35、45℃的pH7缓冲液中的水解半衰期分别为20.81、11.53、6.80和2.14d,平均温度效应系数为2.22。苯醚甲环唑水解反应的平均活化能和活化焓分别为55.53kJ/mol和53.01kJ/mol,而苯醚甲环唑水解反应的活化熵随温度升高而降低,表现出明显的相关性,其平均活化熵为-92.45kJ/mol·k。(3)在相同的培养条件下,苯醚甲环唑在池塘水、河水和超纯水中的降解速率是不同的,其水解半衰期分别为7.31、4.47和12.49d。

Hydrolysis of Difenoconazole

The hydrolysis kinetics of difenoconazole were studied in aqueous solutions.Results were obsevred as follows：（1） Hydrolysis of difenoconazole increased as the pH value of the solution went up,and its hydrolysis half-lives in the buffer solutions of pH 5,pH 7 and pH 9 were 315.07,11.53 and 1.33 d at the temperature of 25℃.（2） Hydrolysis of difenoconazole in the buffer solutions of pH 7 increased as the temperature went up.Hydrolysis half-lives were 20.81,11.53,6.80 and 2.14 d at the temperature of 15,25,35 and 45℃,and the temperature coefficient of hydrolysis for difenoconazole was 2.22.The mean activation enegry（E） and enthalpy（△H） for hydrolysis of difenoconazole was 55.53 kJ/mol and 53.01 kJ/mol.The activation entropy（△S） decreased as the temperature went up,and the mean activation entropy was-92.45 kJ/mol·k.（3） Hydrolysis half-lives of difenoconazole in natural water such as pond water,river water and ultra-pure water were 7.31,4.47 and 12.49 d when the culture conditions were the same.