【摘要】 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。更多还原

【Abstract】 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. T his article proposes energy transfer theory based on the low est energy principle by systematically analyzing ionization processes. T he 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 W aals’ force. T he ionization of samples is the result of the interactions among multiple forces. During different stages of the ionization process,different forces lead to different effects. T here are competition betw een evaporation and formation of multicharge ions for charges. For molecules w ith different structures,Gibbs free energy betw een tw o phases from the changes of molecule shape or conformation may lead to ion evaporation,multiply charged macromolecule and chain ejection,etc. T he energy transfer theory can simplify the three existing theories,as w ell as explain the solvent effect and electrolyte ion effect during ionization process. T he proposed theory provides foundation to optimize the detection condition for different samples and to understand the real process of ionization.更多还原