Collisional cooling of large ions in electrospray mass spectrometry
Collisional cooling of large ions in electrospray mass spectrometry
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DOI：
10.1021/ac035406j
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发表时间：
2004-03-15
影响因子：
7.4
通讯作者：
Thomson, BA
中科院分区：
文献类型：
--
作者：
Chernushevich, IV;Thomson, BA
在仅射频的多极波导中离子的碰撞冷却已经成为将电喷雾源耦合到各种质量分析器的一种选择方法。通常，这种离子导向器的参数（长度、压力）为宽质量范围内的离子提供足够的热化和聚焦。然而，非共价复合物具有比类似质量的变性生物分子更紧凑的构象，因此可能无法通过标准离子导向器有效地传输，如理论分析、模拟和实验所证明的。已经在四极飞行时间仪器上开发了几种改善大的紧凑离子的碰撞冷却的方法，其包括在更高的压力下操作离子导向器和捕获离子以增加冷却时间。在实验中研究了用这些方法获得的重离子的传输改善与蛋白酶体20 S，低聚蛋白质非共价复合物的分子量约692 000，和一些其他化合物。
Collisional cooling of ions in the rf-only multipole guides has become a method of choice for coupling electrospray sources to various mass analyzers. Normally parameters of such ion guides (length, pressure) provide enough thermalization and focusing for ions in a wide mass range. Noncovalent complexes, however, have more compact conformations than denatured biomolecules of similar mass and, therefore may not be transmitted efficiently through standard ion guides, as demonstrated by theoretical analysis, simulations, and experiments. Several methods of improving collisional cooling for large compact ions have been developed on a quadrupole time-of-flight instrument, which include operating the ion guides at higher pressure and trapping ions to increase the cooling time. Improved transmission of heavy ions obtained with those methods is studied in experiments with proteasome 20S, an oligomeric protein noncovalent complex with molecular weight around 692 000, and a few other compounds.