摘要
研究温度对印楝素A、6-deacetylnimbin、6-deacetylsalannin、nimbin和salannin 5种同系物稳定性的影响。建立在不同温度条件下印楝素A及同系物的一级降解动力学模型,计算印楝素A及同系物降解反应的反应速率常数、温度效应系数(Q)、活化能(Ea)、活化焓(?H)和活化熵(?S)。结果表明,印楝素A及同系物在25℃条件下较为稳定,大于35℃时降解速率明显增大。印楝素A、6-deacetylnimbin、6-deacetylsalannin、nimbin和salannin 5种同系物的活化能分别为98.49kJ/mol、92.43kJ/mol、96.76kJ/mol、95.23kJ/mol和104.79kJ/mol,活化焓分别为95.84kJ/mol、89.78kJ/mol、94.11kJ/mol、92.58kJ/mol和102.14kJ/mol,活化熵分别为10.68kJ/mol·K、1.60kJ/mol·K、19.58kJ/mol·K、4.76kJ/mol·K和27.32kJ/mol·K。印楝素A及同系物在环境中的降解反应是自发反应,在环境中易自然降解。
The temperature was systematically investigated to explain its influence to degradation reaction grade, reaction rate coefficient, temperature effect quotient （Q）, activation energy （Ea）, activation enthalpy （AH） and activation entropy （AS） of azadirachtin-A, 6-deacetylnimbin, 6-deacetylsalannin, nimbin and salannin. The test showed that when the reaction temperature was within the range under 25℃, azadirachtin were stable. When temperature was higher than 35℃, the degradation rates were accelerated, and the degradation rate were biggest at 65℃ Degradation of azadirachtin followed the first-order kinetic equation. The Ea of azadirachtin-A, 6-deacetylnimbin, 6-deacetylsalannin, nimbin and salannin were 98.49 kJ/mol, 92.43 kJ/mol, 96.76 kJ/mol, 95.23 kJ/mol and 104.79 kJ/mol respectively. AH of azadirachtin were 95.84 kJ/mol, 89.78 kJ/mol, 94.11 kJ/mol, 92.58 kJ/mol and 102.14 kJ/mol respectively. AS of azadirachtin were 10.68 kJ/mol.K, 1.60 kJ/mol.K, 19.58 kJ/mol.K, 4.76 kJ/mol.K and 27.32 kJ/mol.K respectively. Azadirachtin belonged to easily degraded insecticide, these degradation reactions were spontaneous reactions.
出处
《现代农药》
CAS
2007年第6期30-34,37,共6页
MODERN AGROCHEMICALS
基金
中国热带农业科学院院基金资助项目(RKY0703)
关键词
印楝素
温度
降解
动力学
azadirachtin
temperature
degradation
kinetics
