Poncelet D, Pauss A, Naveau H, Frere J M, Nyns E J
Anal Biochem. 1985 Nov 1;150(2):421-8. doi: 10.1016/0003-2697(85)90531-7.
Generic equations and algorithms are derived to compute, in complex (bio)chemical systems at equilibrium, the following physicochemical parameters: pH (or the concentration of any chemical species), partitions between acid and base forms, global charge, molar mean charges, ionic strength, and molar mean contributions to ionic strength. The model only requires the knowledge of existing thermodynamic constants and of the composition of the system in chemical species as the sum of the different forms other than the species under examination. It takes ionic strength aspects into consideration. Several innovations simplify the computation process: use of polyacidity constants, generalized expression of molar parameters, computation of global parameters from molar mean contributions, simplified corrections for activity, and easy iterative process for pH determination. The model always elicits a unique equilibrium state, namely, it always yields a unique pH value. Computed values always agreed with experimental measurements, thereby validating the model. Digital computer programs were prepared to use the proposed algorithms, which are also a very simple and easy way, compared to the available mathematical descriptions, to solve the problem "manually" without computer facilities.
推导了通用方程和算法，用于计算处于平衡状态的复杂（生物）化学系统中的以下物理化学参数：pH值（或任何化学物质的浓度）、酸碱形式之间的分配、总电荷、摩尔平均电荷、离子强度以及对离子强度的摩尔平均贡献。该模型仅需要了解现有的热力学常数以及系统中化学物质的组成，即除所研究物质之外的不同形式的总和。它考虑了离子强度方面。有几项创新简化了计算过程：使用多元酸度常数、摩尔参数的广义表达式、根据摩尔平均贡献计算全局参数、简化的活度校正以及用于pH测定的简便迭代过程。该模型始终引出唯一的平衡状态，即它始终产生唯一的pH值。计算值始终与实验测量值一致，从而验证了该模型。编写了数字计算机程序来使用所提出的算法，与现有的数学描述相比，这也是一种非常简单易行的方法，可以在没有计算机设备的情况下“手动”解决问题。
