Factors influencing the electrospray intrasource separation and selective ionization of glycerophospholipids
Factors influencing the electrospray intrasource separation and selective ionization of glycerophospholipids
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DOI：
10.1016/j.jasms.2005.11.003
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发表时间：
2006-02-01
影响因子：
3.2
通讯作者：
Gross, RW
中科院分区：
文献类型：
--
作者：
Han, XL;Yang, K;Gross, RW
外部电场导致输注液中的阳离子与负电解质离子分离，同时在电喷雾电离过程中可以以正离子或负离子模式诱导具有不同电倾向的分子种类的差异电离。电喷雾离子源中发生的这些物理和电过程已用于选择性电离具有不同电倾向的脂质类别，现在称为“源内分离和选择性电离”。然而，负责脂质类别选择性电离的电离效率的电荷依赖性改变的化学原理尚不清楚。在此，我们研究了在最佳仪器条件下有助于脂质类别的源内分离和选择性电离的多种因素。我们证明，许多不同的脂质类别可以在离子源中选择性电离，并且在大多数实验条件下，不同分子成分的源内分辨率与脂质浓度、流速和残留离子无关。此外，碱性条件的存在通过独立于 ESI 离子源设计的机制促进许多脂质类别的选择性电离。总的来说，这项研究为理解脂质类别的源内分离和选择性电离的化学机制提供了经验基础，这些机制有可能用于细胞脂质组的全局分析，而无需色谱分离。
The external electric field induces a separation of cations from negative electrolyte ions in the infusate while differential ionization of molecular species that possess differential electrical propensities can be induced in either the positive- or negative-ion mode during the electrospray ionization process. These physical and electrical processes that occur in the electrospray ion source have been used to selectively ionize lipid classes possessing different electrical propensities that are now known as "intrasource separation and selective ionization". However, the chemical principles underlying charge-dependent alterations in ionization efficiencies responsible for the selective ionization of lipid classes are not known with certainty. Herein, we examined the multiple factors that contribute to intrasource separation and selective ionization of lipid classes under optimal instrumental conditions. We demonstrated that many different lipid classes could be selectively ionized in the ion source and that intrasource resolution of distinct molecular constituents was independent of lipid concentration, flow rate, and residual ions under most experimental conditions. Moreover, the presence of alkaline conditions facilitates the selective ionization of many lipid classes through a mechanism independent of the design of the ESI ion source. Collectively, this study provides an empirical foundation for understanding the chemical mechanisms underlying intrasource separation and selective ionization of lipid classes that can potentially be used for global analysis of cellular lipidomes without the need for chromatographic separation.