在城市大气中形成臭氧的碳化合物的较大池
Nature
|June 24, 2000
概括
改进的气体染色学分析识别了城市空气中的500多种挥发性有机化合物. 这一发现表明,以前的污染评估可能低估了这些化合物对空气质量和臭氧形成的影响.
科学领域:
- 环境化学环境化学
- 大气科学 大气科学
- 分析化学 分析化学
背景情况:
- 挥发性有机化合物 (VOC) 是城市光化学烟雾和热层臭氧的关键前体.
- 准确预测污染事件需要识别主导反应性VOC物种.
- 目前的单列色谱缺乏详细的城市大气化学表征的分辨率.
研究的目的:
- 提出一个改进的方法,详细的城市空气的化学特征.
- 加强挥发性有机化合物的识别和分类.
- 重新评估VOCs对城市污染和臭氧形成的贡献.
主要方法:
- 开发一种改进的峰值解卷方法.
- 双列 (直角) 气相色谱的应用.
- 在城市空气样本中分离和分类了500多种挥发性有机物种.
主要成果:
- 成功地分离和分类了500多种挥发性有机物种.
- 确定了100多种多替代的单芳香和挥发性氧化碳化合物.
- 在之前的评估中显示了对活性碳物种的严重低估.
结论:
- 改进的方法为城市大气组成提供了前所未有的细节.
- 以前的污染模型可能低估了特定VOCs的作用,特别是那些具有>6个碳原子的VOCs.
- 纳入这些新发现的VOC将提高光化学臭氧产量和二次有机气溶形成模型.
相关概念视频
Microbes and Climate Change
52
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...
52
Carbon-dioxide Fixation
873
Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...
873
Oxidative Cleavage of Alkenes: Ozonolysis
13.7K
In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
13.7K
The Sulfur Cycle
53.5K
Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the atmosphere as sulfur dioxide (SO2), sulfur is released by decaying organisms, weathered rocks, geothermal vents, volcanos, and burning fossil fuels. It is deposited into the ecosystem, cycled through the biotic community, and either released back into the atmosphere as gas or deposited in marine sediment for long-term storage and eventual...
53.5K
The Carbon Cycle
45.6K
Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
45.6K
Organic Compounds
58.8K
All living things are formed mostly of carbon compounds called organic compounds. The category of organic compounds includes both natural and synthetic compounds that contain carbon. Although a single, precise definition has yet to be identified by the chemistry community, most agree that a defining trait of organic molecules is the presence of carbon as the principal element, bonded to hydrogen and other carbon atoms. However, some carbon-containing compounds such as carbonates, cyanides, and...
58.8K


