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来自1-10 MDa盐集群的离子辐射:单个电荷状态分辨率与电荷检测质谱学
Matthew S McPartlan1, Conner C Harper1, Emeline Hanozin1
1Department of Chemistry, University of California, Berkeley, California, 94720-1460, USA. erw@berkeley.edu.
The Analyst
|January 8, 2024
概括
电荷检测质谱仪可以分析高达10MDa的大盐离子. 这种方法揭示了水化水平和离子排放事件,进步了对电喷离子化中的离子形成的理解.
科学领域:
- 分析化学 分析化学
- 物理化学 物理化学
- 质谱测量质量谱测量
背景情况:
- 电子喷雾电离 (ESI) 产生盐群离子,对于质量校准和研究群稳定性至关重要.
- 之前的ESI研究仅限于较小的集群,因为在更大,多重充电的集群中信号异质.
- 传统的质量到电荷 (m/z) 频谱中未解决的信号阻碍了对大型异质星团的分析.
研究的目的:
- 使用电荷检测质谱法 (CDMS) 描述大型多电荷盐群离子 (KCl,CaCl2,LaCl3) 的质量和电荷分布.
- 调查水合和离子排放在这些大型星团的电荷分离过程中的作用.
- 开发一种新的方法来解决单个离子损失事件,并了解晚期离子形成.
主要方法:
- 使用电荷检测质谱仪 (CDMS) 来测量被困1秒的单个离子的质量和电荷.
- 动态记录每电荷的能量 (m/z),电荷和被困离子的质量.
- 开发了一种基于频率的方法来量化来自单个离子发射事件的电荷损失,解决了+1和+2离子的损失.
主要成果:
- 成功分析了带正电荷的KCl,CaCl2和LaCl3集群,其质量大约在1到10 MDa之间.
- 确定了集群水化程度,按照KCl < CaCl2 < LaCl3的顺序,低于纯水纳米滴.
- 观察到离子排放事件的数量与水合相关,这表明水有助于电荷损失.
- 实现了离子发射事件的单个电荷状态分辨率,这是研究离子形成的重大进展.
结论:
- CDMS对于分析大型多电荷盐群离子是有效的,克服了传统质谱学的局限性.
- 化水平和水结合强度影响盐集群的离子排放和电荷损失.
- 开发的基于频率的方法为ESI中裸体气态离子形成的后期阶段提供了详细的见解.
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