Institute for Pure and Applied Mass Spectrometry, Physical and Theoretical Chemistry, University of Wuppertal, 42119, Wuppertal, Germany.
SCIEX, 71 Four Valley Drive, Concord, ON, L4K 4V8, Canada.
Anal Bioanal Chem. 2021 Sep;413(22):5587-5600. doi: 10.1007/s00216-021-03452-y. Epub 2021 Jul 2.
Electrospray ionization (ESI) generates bare analyte ions from charged droplets, which result from spraying a liquid in a strong electric field. Experimental observations available in the literature suggest that at least a significant fraction of the initially generated droplets remain large, have long lifetimes, and can thus aspirate into the inlet system of an atmospheric pressure ionization mass spectrometer (API-MS). We report on the observation of fragment signatures from charged droplets penetrating deeply the vacuum stages of three commercial mass spectrometer systems with largely different ion source and spray configurations. Charged droplets can pass through the ion source and pressure reduction stages and even into the mass analyzer region. Since droplet signatures were found in all investigated instruments, the incorporation of charged droplets is considered a general phenomenon occurring with common spray conditions in ESI sources.
电喷雾电离（ESI）从带电液滴中生成裸分析物离子，这些液滴是通过在强电场中喷雾产生的。文献中提供的实验观察结果表明，最初生成的液滴中至少有很大一部分仍然很大，寿命很长，因此可以吸入大气压电离质谱仪（API-MS）的入口系统。我们报告了在观察带有电荷的液滴穿透三种商业质谱仪系统的真空级时的碎片特征的情况，这三种质谱仪系统的离子源和喷雾配置有很大的不同。带电液滴可以穿过离子源和减压阶段，甚至进入质量分析器区域。由于在所有研究的仪器中都发现了液滴特征，因此可以认为，带电液滴的进入是在 ESI 源中常见的喷雾条件下普遍发生的现象。
