Starting with the Rayleigh charge limiting model, a slightly different approach is used to account for the well-known discrepancy that exists between the said model and experimental ESI MS data for globular proteins. It is shown using published datasets that for globular proteins, the mass density ρ exhibits a weak second-order dependence on its mass M, according to ρ(M)∝ M^-α, α ~ 0.14. A direct equivalence established between ESI MS and x-ray techniques suggests a minimum but critical surface tension of 15.6 ± 5.2 mN/m for the droplet at the liquid-to-gas phase transition point. The packing density factor η for globular proteins is believed to lie between 1 (very tightly packed) and 4.6 (less tight, natively packed). While the Rayleigh charge limiting model has been linked historically to the CRM (J. Chem. Phys. 49:2240–2249, 1968; Anal. Chim. Acta 406:93–104, 2000), this paper does not expressly seek to justify the CRM, but rather uses empirical data and existing knowledge across subfields to help build a consistent picture of ESI MS phenomena that might be difficult to explain otherwise. These results would be useful in molecular dynamics (MD) simulations, understanding liquid-to-gas phase transitions and in opening up new routes for cross-calibration between ESI MS, IM MS, NMR and x-ray crystallography studies.

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从瑞利电荷限制模型开始，使用略有不同的方法来解释所述模型与球蛋白的实验ESI MS数据之间存在的众所周知的差异。使用已发布的数据集表明，对于球形蛋白质，质量密度ρ根据其质量M表现出较弱的二阶依赖性，根据ρ（M）∝ M- ^α，α〜0.14。在ESI MS和X射线技术之间建立的直接等效性表明，液滴在液相到气相的过渡点的最小但临界表面张力为15.6±5.2 mN / m。据信球状蛋白的堆积密度因子η在1（非常紧密堆积）和4.6（较不紧密，自然堆积）之间。虽然瑞利电荷限制模型已经历史链接到CRM（J.化学物理49：2240至2249年，。。1968 ;分析詹ACTA 406：93-104，2000），本文并没有明确地证明CRM的合理性，而是使用经验数据和跨子领域的现有知识来帮助建立ESI MS现象的一致图景，否则可能难以解释。这些结果将对分子动力学（MD）模拟，理解液相到气相的相变以及为ESI MS，IM MS，NMR和X射线晶体学研究之间的交叉校准开辟新途径提供有用的信息。

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