电喷雾离子源（electrospray ionization，ESI）不仅可以用于小分子的检测，也能够用于蛋白质、多肽等大分子的研究。本文通过对离子化过程的系统分析，提出了基于能量最低原理的离子化过程能量转移理论。样品分子在由液相转移到气相形成离子化气体的过程中受到静电力、分子间的范德华力等多种力的作用。样品的离子化是多种力共同作用的结果，在不同的离子化阶段，不同形式的力的作用也不尽相同。电荷在样品表面蒸发和多电荷离子的形成之间存在竞争。对不同结构的分子，分子形态、构象改变导致的两相间转移 Gibbs 自由能变化不同，可能导致离子蒸发、大分子形成多电荷离子、产生链弹射等行为。离子化能量转移理论不仅能够对已有的3种理论加以简化统一，也可以说明溶剂、电解质离子等在离子化过程中的作用，为优化不同结构与形态样品的质谱检测、了解离子化的真实过程提供了一种可能的依据。%Electrospray ionization source(ESI)can be used not only for the detection of small molecules,but also for large molecules such as proteins and peptides. This article proposes energy transfer theory based on the lowest energy principle by systematically analyzing ioniza-tion processes. The transference of the analyte from liquid phase to gas phase can be influenced by multiple forces during the ionization and vaporization processes,such as electrostatics force and van der Waals’force. The ionization of samples is the result of the interactions among mul-tiple forces. During different stages of the ionization process,different forces lead to different effects. There are competition between evaporation and formation of multi-charge ions for char-ges. For molecules with different structures,Gibbs free energy between two phases from the changes of molecule shape or conformation may lead to ion evaporation,multiply charged mac-romolecule and chain ejection,etc. The energy transfer theory can simplify the three existing theories,as well as explain the solvent effect and electrolyte ion effect during ionization process. The proposed theory provides foundation to optimize the detection condition for differ-ent samples and to understand the real process of ionization.
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