提取式电子喷雾对模型系统和二次有机气溶的灵敏度限制
David M Bell1, Jun Zhang1, Jens Top1
1Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen 5232, Switzerland.
Analytical chemistry
|September 1, 2023
概括
这项研究引入了一种使用热剥离器 (TD) 的新方法,通过根据挥发性分离分子来量化气溶的化学成分. 这种方法提高了复杂有机气溶的提取电喷气离子化飞行时间质谱 (EESI-TOF) 测量的精度.
科学领域:
- 大气化学 大气化学
- 分析化学 分析化学
- 质谱测量质量谱测量
背景情况:
- 鉴定气溶化学成分的量化是具有挑战性的,因为检测方法中的物种敏感性是可变的.
- 软电离技术,如EESI-TOF,表现出分子依赖的反应因子,使准确的测量变得复杂.
- 了解气溶成分对于大气科学和气候建模至关重要.
研究的目的:
- 开发和验证一种使用EESI-TOF精确量化气溶化学成分的方法.
- 为了应对EESI-TOF测量中的分子依赖灵敏度的挑战.
- 确定EESI-TOF对复杂有机气溶中不同类别分子的灵敏度.
主要方法:
- 使用热剥离器 (TD) 来根据挥发性分离气溶组件.
- 使用扫描移动粒子测量器 (SMPS) 来量化质量损失,并将其与EESI-TOF信号损失进行比较.
- 通过使用聚乙烯糖醇 (PEG-300) 和α-平烯二次有机气溶 (SOA) 确定了EESI-TOF灵敏度.
主要成果:
- TD成功地根据挥发性分离了分子,允许在EESI-TOF中确定分子特定的灵敏度.
- 在简化混合物中,EESI-TOF对更易挥发的分子的敏感性更高.
- 对于α-pinene SOA,灵敏度校正将测量分布从60.1%的单体转移到37.4%,从32.7%的二元转移到56.1%.
结论:
- TD-EESI-TOF方法为准确量化气溶化学成分提供了一条途径,特别是对于像SOA这样的复杂混合物.
- 这种方法使得分子类 (单体,二极体,寡聚体) 的分化能够基于波动性和修正的灵敏度.
- 这些发现适用于各种分析挑战和潜在的大气测量,需要精确的气溶表征.
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