This study investigated the formation and environmental fate of radicals on tabacco pyrolysis residues using electron para-magnetic resonance( EPR) spectroscopy. Results indicate that during tabacco pyrolysis,large quantities of free radicals formed on the pyrolysis residues. The radicals were mainly oxygen-centered radicals when tabacoo was pyrolyzed at low tempeatures(400-500℃), whereas they were mainly carbon-centered radicals at higher pyrolysis temperatures(600-700℃). When tabacco pyrolysis residues were exposed to air,new oxygen-centered radicals were formed within the first 60-120 min of exposure,which increased the radical quantiy on the pyrolysis residues. The quantities and types of radicals then did not change much with prolonged exposure,and they could exist in the environment for a long period.%使用顺磁共振波谱技术研究了烟草热解残余物中自由基的形成及其在环境中的转化。研究结果表明：烟草热解时会在其残余物上形成大量自由基。热解温度较低时(400~500℃)主要形成以O原子为中心的自由基，而热解温度较高(600~700℃)时，主要形成以C原子为中心的自由基。烟草热解残余物与空气接触后，会生成新的以O原子为中心的自由基，从而使自由基数量在短时间(60~120 min)内增加，随后自由基数量和种类趋于稳定，并可长期存在于环境中。
展开▼
