Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, the Netherlands.
Netherlands Proteomics Center, Utrecht, the Netherlands.
Nat Chem. 2022 May;14(5):515-522. doi: 10.1038/s41557-022-00897-1. Epub 2022 Mar 10.
To enhance the performance of charge-detection mass spectrometry, we investigated the behaviour of macromolecular single ions on their paths towards and within the Orbitrap analyser. Ions with a mass beyond one megadalton reach a plateau of stability and can be successfully trapped for seconds, travelling a path length of multiple kilometres, thereby enabling precise mass analysis with an effective resolution of greater than 100,000 at a mass-to-charge ratio of 35,000. Through monitoring the frequency of individual ions, we show that these high-mass ions, rather than being lost from the trap, can gradually lose residual solvent molecules and, in rare cases, a single elementary charge. We also demonstrate that the frequency drift of single ions due to desolvation and charge stripping can be corrected, which improves the effective ion sampling 23-fold and gives a twofold improvement in mass precision and resolution.
为了提高电荷检测质谱的性能，我们研究了大分子单离子在通向和进入轨道阱分析器过程中的行为。质量超过 1 兆道尔顿的离子达到稳定的平台，并能成功地被捕获数秒，行进数公里的路程，从而实现精确质量分析，在质荷比为 35,000 时有效分辨率大于 100,000。通过监测单个离子的频率，我们表明这些高质量的离子并没有从陷阱中丢失，而是可以逐渐失去残留的溶剂分子，在极少数情况下，失去一个单个的基本电荷。我们还证明，由于去溶剂化和电荷剥离导致的单离子频率漂移可以得到校正，这将有效离子采样提高了 23 倍，并将质量精度和分辨率提高了两倍。
