Enke C G
Department of Chemistry, University of New Mexico, Albuquerque 87131-1096, USA.
Anal Chem. 1997 Dec 1;69(23):4885-93. doi: 10.1021/ac970095w.
In electrospray ionization (ESI), droplets with a surface excess charge are created. The rate of production of surface excess charge is a constant and is equal to the rate of ion production. The ions appearing in the mass spectrum are postulated to be those that formed the surface excess charge at the time of droplet formation (or their collision products). An equilibrium model based on competition among the ions in the solution for the limited number of excess charge sites has been developed. This model accurately predicts the response curves of singly-charged ionic analytes as a function of the concentration of electrolyte and other analytes and provides an explanation for the selective effectiveness of ESI. At low concentrations of total analyte (micromolar and less), the response curves are linear, indifferent to the presence of other low concentration analytes, and suppressed by electrolyte concentrations in excess of the minimum required. At higher analyte concentrations, the response becomes independent of analyte concentration but highly affected by the presence of other analytes.
在电喷雾电离（ESI）过程中，会产生具有表面过剩电荷的液滴。表面过剩电荷的产生速率是恒定的，且等于离子产生速率。质谱中出现的离子被假定为在液滴形成时形成表面过剩电荷的那些离子（或它们的碰撞产物）。基于溶液中离子对有限数量的过剩电荷位点的竞争，已开发出一种平衡模型。该模型准确地预测了单电荷离子分析物的响应曲线与电解质和其他分析物浓度的函数关系，并为ESI的选择性效果提供了解释。在总分析物浓度较低（微摩尔及以下）时，响应曲线是线性的，不受其他低浓度分析物存在的影响，但会被超过最低要求的电解质浓度所抑制。在较高的分析物浓度下，响应变得与分析物浓度无关，但受到其他分析物存在的高度影响。
