在用氧化酸消化土壤时,出现意想不到的二氧化物形成
Wenjing Xie1, Wenjuan Li1, Pu Wang1
1Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, School of Environment and Health, Jianghan University, Wuhan 430056, China.
Environmental science & technology
|September 8, 2023
概括
意外的二氧化 (PCDD/Fs) 形成发生在土壤和有机基质在水域消化过程中. 胺酸是关键的前体,突出了实验室过程的潜在风险.
科学领域:
- 环境化学环境化学
- 分析化学 分析化学
- 有机化学 有机化学
背景情况:
- 二氧化物,特别是多二子-p-二氧化物和二酸 (PCDD/Fs),是高度有毒的无意持续性有机污染物.
- 它们的排放是一个重大的环境问题,需要对形成途径进行研究.
研究的目的:
- 通过使用皇家水 (aqua regia) 来研究土壤和有机基质的消化过程中二氧化的形成.
- 确定土壤有机物成分在二氧化物产生中的作用.
主要方法:
- 用国水6小时消化土壤和含有有机碳的样本.
- 量化 Σ17PCDD/Fs 度和WHO2005-TEQ 值.
- PCDD/Fs度与土壤有机碳含量之间的相关性分析.
主要成果:
- 在土壤和各种有机基质中观察到大量的二氧化物形成,这些物质在水域化后被消化.
- Σ17PCDD/Fs度在 66.6-142,834 pg/g dw 之间,与土壤有机碳正相关 (R2 = 0.89).
- 酸被确定为PCDD/PCDF形成的重要前体,比纤维素或红素更重要.
结论:
- 水域消化可以导致大量的无意的二氧化物形成,特别是在富含湿物质的样本中.
- 强烈的氧化和水的反应性生产可能是关键因素.
- 中国的检验和测试行业估计的年度排放量很大 (83.8g TEQ),需要注意实验室实践.
更多相关视频
相关概念视频
01:20Radical Autoxidation
2.2K
The oxidation of an organic compound in the presence of air or oxygen is called autoxidation. For example, cumene reacts with oxygen to form hydroperoxide. Autoxidation involves initiation, propagation, and termination steps. Many organic compounds are susceptible to autoxidation—especially ethers in the presence of oxygen, which form hydroperoxides. Even though this reaction is slow, old ether bottles contain small amounts of peroxide, which leads to laboratory explosions during ether...
2.2K
02:04Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
5.9K
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
5.9K
01:08Sample Preparation for Analysis: Advanced Techniques
389
Accurate analysis of complex samples often requires advanced preparation techniques to achieve reliable and reproducible results. Samples containing inorganic or organic materials can be challenging to dissolve or decompose effectively. Standard sample preparation methods include acid digestion, fusion, dry ashing, and wet digestion.
Acid digestion with strong acids is commonly used to dissolve inorganic materials that are insoluble (do not dissolve) in water. This method can be useful for...
Acid digestion with strong acids is commonly used to dissolve inorganic materials that are insoluble (do not dissolve) in water. This method can be useful for...
389
01:36Types of Toxins
1.7K
Humans continually engage with an environment rich in potentially harmful chemicals. These are introduced to our bodies through inhalation, ingestion, or skin contact. These chemicals exist in various forms, such as air and environmental pollutants, agricultural chemicals, organic solvents, and heavy metals.
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...
1.7K
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
10.3K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
10.3K
02:37Oxidation of Alcohols
13.3K
In this lesson, the oxidation of alcohols is discussed in depth. The various reagents used for oxidation of primary and secondary alcohols are detailed, and their mechanism of action is provided.
The process of oxidation in a chemical reaction is observed in any of the three forms:
The process of oxidation in a chemical reaction is observed in any of the three forms:
13.3K