Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States.
Anal Chem. 2013 May 21;85(10):5103-13. doi: 10.1021/ac400447k. Epub 2013 Apr 29.
We present a model capturing the important contributors to the effects of temperature on the observable electrophoretic mobilities of small ions, and on solution conductivity and pH. Our temperature model includes relations for temperature-dependent viscosity, ionic strength corrections, degree of ionization (pK), and ion solvation effects on mobility. We incorporate thermophysical data for water viscosity, temperature-dependence of the Onsager-Fuoss model for finite ionic strength effects on mobility, temperature-dependence of the extended Debye-Huckel theory for correction of ionic activity, the Clarke-Glew approach and tabulated thermodynamic quantities of ionization reaction for acid dissociation constants as a function of temperature, and species-specific, empirically evaluated correction terms for temperature-dependence of Stokes' radii. We incorporated our model into a MATLAB-based simulation tool we named Simulation of Temperature Effects on ElectroPhoresis (STEEP). We validated our model using conductivity and pH measurements across a temperature variation of 25-70 °C for a set of electrolytes routinely used in electrophoresis. The model accurately captures electrolyte solution pH and conductivity, including important effects not captured by simple Walden-type relations.
我们提出了一个模型，该模型捕捉了温度对小离子的可观测电泳迁移率、溶液电导率和 pH 值的影响的重要贡献因素。我们的温度模型包括与温度相关的粘度、离子强度校正、离解度（pK）以及离子溶剂化对迁移率的影响的关系。我们结合了水粘度的热物理数据、有限离子强度对迁移率的 Onsager-Fuoss 模型的温度依赖性、修正离子活度的扩展 Debye-Huckel 理论的温度依赖性、Clarke-Glew 方法和酸碱离解常数随温度变化的表列热力学量，以及针对 Stokes 半径的温度依赖性的经验评估校正项。我们将模型集成到一个基于 MATLAB 的模拟工具中，命名为 Simulation of Temperature Effects on ElectroPhoresis（STEEP）。我们使用电泳中常用的一组电解质在 25-70°C 的温度变化范围内进行电导率和 pH 值测量来验证我们的模型。该模型准确地捕捉了电解质溶液的 pH 值和电导率，包括简单的 Walden 型关系无法捕捉的重要影响。
