Theoretical fate studies of O-ethyl O-4-nitrophenyl phenylphosphonothioate (EPN) by electrochemical method and chromatographic techniques.

• Main Authors: E-Ming Cheng, 陳一銘
• Other Authors: Jen-Fon Jen
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/69460141627925072474

碩士 === 國立中興大學 === 化學系 === 89 === Degradation of O-ethyl O-4-nitrophenyl phenylphosphonothioate (EPN) was investigated with electrochemical reaction and chromatographic determination. EPN was oxidized and reduced electrochemically with the potential of +600mV and —800mV, respectively. Both the oxidation and reduction products as well as the reactant were analyzed by HPLC-UV and identified by related analytical techniques. After series studies, a scheme for possible degradation pathway was thus built-up. The degradation reactions were also studied kinetically. Experiment results indicate that the degradation of EPN was followed the apparent first-order reaction. The rate constants for electrochemical degradation were 0.0017min-1 for oxidation and 0.05968min-1 for reduction. The rate constants increase with the basicity of solution. There was no significance degradation occurred under the pH value below 9.0 without electrochemical reaction. The rate constants were 0.00116, 0.00405, 0.0117 min-1, for pH 10, 11, 12, respectively.