农药在玻璃表面与正己烷中的光解速率

本文通过测定14种农药在正已烷中和在玻璃表面的光解速率,探讨反应介质对光反应速率的影响,七种拟除虫菊酯农药中,具有α-氰基的五种农药的光解速率明显快于结构上不含α-氰基的二氯苯醚菊酯和联苯菊酯;七种有机磷农药中,具有较大共轭体系的农药光解速率较快,农药在正已烷中与在玻璃表面的光解速率常数之间存在高度相关关系(γ=0.991,n=12),两套数据间的定量关系为y=-3.07×10~(-4)+1.67x。

PHOTOLYSIS RATES OF PESTICIDES ON GLASS SURFACE AND IN HEXANE

The photolysis rates of 14 pesticides in hexane and on glass surface were determined. The pesticides were irradiated in a photochemical reactor.The pesticide concentration was determined by gas chromatography. Among the 7 pyrethroid pesticides those with al-pha-cyano group in the molecule photolyzed much faster than per-methrin and biphenthrin, two pyrethroids without the alpha-cyano group. Among the 7 organophosphorus pesticides, those with aromatic structure in molecule have half lives shorter than 7 minutes in hexane, whereas those without aromatic structure, such as dime-thoate, malathion, and bithion, have half lives longer than 100 minutes. The photolysis rates constants in hexans are significantly correlated to those on glass surface with a correlation coefficient of 0.991(n=12).