• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Early Chemistry of Nicotine Degradation in Heat-Not-Burn Smoking Devices and Conventional Cigarettes: Implications for Users and Second- and Third-Hand Smokers
【24h】

Early Chemistry of Nicotine Degradation in Heat-Not-Burn Smoking Devices and Conventional Cigarettes: Implications for Users and Second- and Third-Hand Smokers

机译：尼古丁的早期化学在热非燃烧吸烟装置和传统卷烟中的降解：对用户的影响和第二和三手吸烟者

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Nicotine exposure results in health risks not only for smokers but also for second- and third-hand smokers. Unraveling nicotine's degradation mechanism and the harmful chemicals that are produced under different conditions is vital to assess exposure risks. We performed a theoretical study to describe the early chemistry of nicotine degradation by investigating two important reactions that nicotine can undergo: hydrogen abstraction by hydroxyl radicals and unimolecular dissociation. The former contributes to the control of the degradation mechanism below 800 K due to a non-Arrhenius kinetics, which implies an enhancement of reactivity as temperature decreases. The latter becomes important at higher temperatures due to its larger activation energy. This change in the degradation mechanism is expected to affect the composition of vapors inhaled by smokers and room occupants. Conventional cigarettes, which operate at temperatures higher than 1000 K, are more prone to yield harmful pyridinyl radicals via nicotine dissociation, while nicotine in electronic cigarettes and vaporizers, with operating temperatures below 600 K, will be more likely degraded by hydroxyl radicals, resulting in a vapor with a different composition. Although low-temperature nicotine delivery devices have been claimed to be less harmful due to their non burning operating conditions, the non-Arrhenius kinetics that we observed for the degradation mechanism below 873 K suggests that nicotine degradation may be more rapidly initiated as temperature is reduced, indicating that these devices may be more harmful than it is commonly assumed.
机译：尼古丁接触不仅会给吸烟者带来健康风险，还会给二手和三手吸烟者带来健康风险。弄清尼古丁的降解机制以及在不同条件下产生的有害化学物质对于评估接触风险至关重要。我们进行了一项理论研究，通过研究尼古丁可能经历的两个重要反应来描述尼古丁降解的早期化学过程：羟基自由基吸氢和单分子离解。由于非阿累尼乌斯动力学，前者有助于将降解机制控制在800K以下，这意味着随着温度降低，反应性增强。后者因其较大的活化能而在较高温度下变得重要。降解机制的这种变化预计会影响吸烟者和房间居住者吸入的蒸汽成分。工作温度高于1000 K的传统香烟更容易通过尼古丁离解产生有害的吡啶基，而工作温度低于600 K的电子香烟和汽化器中的尼古丁更有可能被羟基自由基降解，从而产生具有不同成分的蒸汽。尽管低温尼古丁输送装置因其非燃烧操作条件而被认为危害较小，但我们在873 K以下的降解机制中观察到的非阿累尼乌斯动力学表明，随着温度降低，尼古丁降解可能会更快地开始，这表明这些装置的危害可能比通常认为的更大。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号