关于短脱的酸和多酸以及酒精的单分子分解产物
Angela S Radnoff1, Samuel Charpentier-St-Pierre1, Paul M Mayer1
1Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Canada.
Journal of mass spectrometry : JMS
|September 9, 2025
概括
这项研究使用双重质谱学量化每和多化基物质 (PFAS). 我们探讨了无质子化PFAS酒精和酸的分解,揭示了环境分析的关键碎片化途径.
科学领域:
- 环境化学环境化学
- 分析化学 分析化学
- 物理化学 物理化学
背景情况:
- 透和多化基物质 (PFAS) 由于强烈的碳-键而具有环境持久性.
- 双重质谱法是环境样本中PFAS量化的常用方法.
- 无质化PFAS酒精和酸的碎片化途径需要进一步进行定性探索.
研究的目的:
- 调查去化PFAS酒精和酸的解离机制.
- 使用能量解析碰撞诱导解离 (CID) 和密度函数理论来描述碎片化模式.
- 为改善分析方法提供有关特定PFAS化合物分解的详细见解.
主要方法:
- 能量解析碰撞诱导解离 (CID) 串联质谱学.
- 密度函数理论 (DFT) 的计算 (M06/6-311+G(d,p)).
- 对去的2,2,3,3,3-五烯酸,3,3,3-三烯酸,2,2,3,3-五烯-1-醇,3,3,3-三烯-1-醇和三甲硫酸进行分析.
主要成果:
- 确定了关键的碎片化途径,包括各种PFAS离子的CO2,CH2O,HF和H2O的损失.
- 根据RRKM的计算,m/z 83的形成比m/z 63对2离子的形成更有利.
- 离子4的碎片化模式显示,从低能量的m/z95主导转变为高能量的m/z93主导.
- 三甲硫酸 (离子5) 主要分裂为FSO3-,SO3-,和CF3-,由于高电子亲和力,SO3-是最丰富的.
结论:
- 详细的碎片化途径为几个deprotonated PFAS酒精和酸被阐明.
- 该研究为 PFAS 分析中的双重质谱结果的解释提供了关键数据.
- 了解这些解离机制可以提高PFAS在环境矩阵中的量化准确性和可靠性.
更多相关视频
相关概念视频
Mass Spectrometry: Molecular Fragmentation Overview
5.3K
The ionization of a molecule into a molecular ion inside the mass spectrometer causes instability in the molecule's structure due to the loss of an electron. This eventually leads to the fragmentation or breaking of some bonds in the molecule. The fragmentation occurs predominantly at specific bonds to yield relatively stable fragments.
One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can occur at...
One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can occur at...
5.3K
Mass Spectrometry: Alcohol Fragmentation
4.4K
Alcohols (R-OH) ionize to lose one non-bonded electron from the oxygen atom, forming molecular ions. Due to their tendency to fragment rapidly, the intensity of the molecular ion peak in the mass spectrum is weak or sometimes absent. The fragmentation patterns for alcohols occur in two ways, i.e. ⍺-cleavage and dehydration. During ⍺-cleavage, the bond at the ⍺-position adjacent to the hydroxyl group cleaves to give a resonance-stabilized cation and a radical. However, intramolecular...
4.4K
Acid Halides to Carboxylic Acids: Hydrolysis
3.5K
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
3.5K
Acid-Catalyzed Dehydration of Alcohols to Alkenes
23.4K
In a dehydration reaction, a hydroxyl group in an alcohol is eliminated along with the hydrogen from an adjacent carbon. Here, the products are an alkene and a molecule of water. Dehydration of alcohols is generally achieved by heating in the presence of an acid catalyst. While the dehydration of primary alcohols requires high temperatures and acid concentrations, secondary and tertiary alcohols can lose a water molecule under relatively mild conditions.
23.4K
Acid Halides to Esters: Alcoholysis
3.8K
Alcoholysis is a nucleophilic acyl substitution reaction in which an alcohol functions as a nucleophile. Acid halides react with alcohol to produce esters. The mechanism proceeds in three steps:
3.8K
Alkynes to Carboxylic Acids: Oxidative Cleavage
6.7K
Alkynes undergo oxidative cleavage in the presence of oxidizing reagents like potassium permanganate and ozone. The triple bond — one σ bond and two π bonds — is completely cleaved, and the alkyne is oxidized to carboxylic acids. When warm and basic aqueous potassium permanganate is used as an oxidizing agent, alkynes are first converted to carboxylate salts via an unstable α-diketone intermediate. Further, a mild acid treatment protonates the carboxylate anions...
6.7K


