除草剂2-甲基-4-氯苯氧乙酸(MCPA)与~·OH自由基的气相化学反应  

Gas-phase Reaction of Herbicide 2-Methyl-4-chlorophenoxy Acetic Acid(MCPA) with ~·OH Radicals

作　　者：韩蕾[1] 朱彤[1] 孙凤龙[1] 尚静[1] 

机构地区：[1]北京大学环境学院环境模拟与污染控制国家联合重点实验室,北京100871

出　　处：《高等学校化学学报》2006年第1期112-115,共4页Chemical Journal of Chinese Universities

基　　金：国家杰出青年基金(批准号:49925513);国家自然科学基金(批准号:2007001);国家'九七三'计划(批准号:2002CB410802)资助

摘　　要：采用长光程气体池结合傅里叶变换红外光谱仪测得了除草剂2-甲基-4-氯苯氧乙酸(MCPA)与.OH自由基在23℃时的反应速率常数为2.67×10-11cm3/(s.mol),以此估算了在大气中.OH自由基浓度为7×105mol/cm3时,MCPA与.OH自由基反应导致的大气寿命为14.9 h.结果表明,在大气环境中MCPA较容易降解,不会通过大气输送对环境造成广泛和持久性污染.The investigations about the atmospheric degradation of organic herbicides became more and more important in China. In our present research, the rate constant of the reaction of 2-methyl-4-chlorophenoxy acetic acid （MCPA） with ·OH radicals was measured by a long path quartz reactor connecting with Fourier Transform Infrared Spectroscopy（FTIR）. At 23 ℃ and under one atmosphere, the rate constant was determined to be 2.67 × 10^-11cm^3/（ s · mol）, the atmospheric life time of MCPA was estimated to be 14.9 h. The results show that MCPA can be degraded in atmosphere and is not feasible to cause wide-spreading and persisting pollution through long range atmospheric transport.

关 键 词：除草剂 2-甲基-4-氯苯氧乙酸(MCPA) ·OH自由基 反应速率常数 

分 类 号：O644.13[理学—物理化学]