Tao Y, Wells P S, Yi X, Yun K S, Parcher J F
Chemistry Department, University of Mississippi, University 38677, USA.
J Chromatogr A. 1999 Nov 5;862(1):49-64. doi: 10.1016/s0021-9673(99)00887-0.
Lattice-fluid models describe molecular ensembles in terms of the number of lattice sites occupied by molecular species (r-mers) and the interactions between neighboring molecules. The lattice-fluid model proposed by Sanchez and Lacombe (Macromolecules, 1978;11:1145-1156) was used to model specific retention volume data for a series of n-alkane solutes with n-alkane, polystyrene, and poly(dimethylsiloxane) stationary liquid phases. Theoretical equations were derived for the specific retention volume and also for the temperature dependence and limiting (high temperature) values for the specific retention volume. The model was used to predict retention volumes within 10% for the n-alkanes phases; 22% for polystyrene; and from 20 to 70% for PDMS using no adjustable parameters. The temperature derivative (enthalpy) could be calculated within 5% for all of the solutes in nine stationary liquid phases. The limiting value for the specific retention volume at high temperature (entropy controlled state) could be calculated within 10% for all of the systems. The limiting data also provided a new chromatographic method to measure the size parameter, r, for any chromatographic solute using characteristic and size parameters for the stationary phase only. The calculated size parameters of the solutes were consistent, i.e. independent of the stationary phase and agreed within experimental error with the size parameters previously reported from saturated vapor pressure, latent heat of vaporization or density data.
格子流体模型根据被分子物种（r-聚体）占据的格点数量以及相邻分子之间的相互作用来描述分子集合体。Sanchez和Lacombe（《大分子》，1978年；11：1145 - 1156）提出的格子流体模型被用于模拟一系列正构烷烃溶质在正构烷烃、聚苯乙烯和聚二甲基硅氧烷固定液相上的比保留体积数据。推导了比保留体积的理论方程，以及比保留体积的温度依赖性和极限（高温）值的方程。该模型用于预测正构烷烃相的保留体积误差在10%以内；聚苯乙烯的误差在22%以内；聚二甲基硅氧烷的误差在20%至70%以内，且无需可调参数。对于九个固定液相中的所有溶质，温度导数（焓）的计算误差可在5%以内。高温下比保留体积的极限值（熵控制状态）对于所有系统的计算误差可在10%以内。这些极限数据还提供了一种新的色谱方法，仅使用固定相的特征和尺寸参数来测量任何色谱溶质的尺寸参数r。计算得到的溶质尺寸参数是一致的，即与固定相无关，并且在实验误差范围内与先前从饱和蒸气压、汽化潜热或密度数据报道的尺寸参数一致。
