电化学法测定西维因水解速率参数

Determination of hydrolysis rate constant for carbaryl by electrochemical technique

使用现代电化学分析方法,通过监测水解产物的生成情况,研究了本身无电化学活性的西维因(甲萘威)在水中的水解情况,在pH=7.0的BR缓冲液环境中西维因水解产物检测的灵敏度最高.考察了环境酸度以及环境温度对水解的影响,并测定了不同条件下的水解速率常数.发现西维因的水解过程符合一级反应方程,其水解受pH值、温度的影响.在酸性介质中西维因仍有一定的水解,但是水解的速率明显低于碱性介质中的水解速率.同时,环境温度也会影响水解速率,在较高温度下,不论环境酸度值为碱性或者酸性,西维因的水解速率均有所升高.

The hydrolysis behavior of carbaryl was investigated by cyclic voltammetry （CV） and different pulse voltammetry （DPV） at a glassy carbon electrode （ GCE）, and the hydrolysis rate constants at different pH value and temperature were determined. The experiment indicates that the hydrolysis of carbaryl is one order reaction, and the carbaryl also could hydrolyze in acidic medium, but the speed of the hydrolysis was lower than that in alkaline medium. In addition, the temperature 9 obviously affecs the hydrolysis rate in acidic and alkaline medium.