Sublimation Driven Ionization for Use in Mass Spectrometry: Mechanistic Implications
Sublimation Driven Ionization for Use in Mass Spectrometry: Mechanistic Implications
复制标题
用于质谱分析的升华驱动电离：机理意义
DOI：
10.1021/jasms.0c00297
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发表时间：
2020
影响因子：
3.2
通讯作者：
Trimpin, Sarah
中科院分区：
文献类型：
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作者：
McEwen, Charles N.;Inutan, Ellen D.;Moreno-Pedraza, Abigail;Lu, I-Chung.;Hoang, Khoa;Pophristic, Milan;Trimpin, Sarah
升华至少从中世纪就已为人所知。这个过程在学校里经常通过使用相图来教授。令人惊讶的是，这样一个众所周知的过程似乎仍然藏有秘密。在化合物升华发生的条件下，气相离子经常使用质谱法检测。这是利用在真空中的基质辅助电离（vMAI）通过添加分析物升华化合物用作基质。良好的vMAI基质是那些以高灵敏度对添加的分析物进行检测的基质，但即使是未通过该检测的基质也经常产生可能的基质杂质离子，这表明它们可能是某些化合物类型的良好基质。我们还表明，二进制矩阵可以被操纵，以提供所需的性能，如快速分析和提高灵敏度。这些结果意味着升华在某些情况下比仅仅分子离开表面更复杂，并且理解负责的物理力以及非挥发性化合物如何带电，可以提高质谱的电离效率。在这里，我们提供了对这一过程的见解，并解释了为什么这种意想不到的现象以前没有报道过。
Sublimation has been known at least since the middle ages. This process is frequently taught in schools through the use of phase diagrams. Astonishingly, such a well-known process appears to still harbor secrets. Under conditions in which compound sublimation occurs, gas-phase ions are frequently detected using mass spectrometry. This was exploited in matrix-assisted ionization in vacuum (vMAI) by adding analyte to subliming compounds used as matrices. Good vMAI matrices were those that ionize the added analyte with high sensitivity, but even matrices that fail this test often produce ions of likely matrix impurities suggesting that they may be good matrices for some compound types. We also show that binary matrices may be manipulated to provide desired properties such as fast analyses and improved sensitivity. These results imply that sublimation in some cases is more complicated than just molecules leaving a surface and that understanding the physical force responsible, and how the nonvolatile compound becomes charged, could lead to improved ionization efficiency for mass spectrometry. Here we provide insights into this process and an explanation of why this unexpected phenomenon has not previously been reported.