Departament de Química Analítica and Institut de Biomedicina, Universitat de Barcelona, Martí i Franquès 1-11, E-08028 Barcelona, Spain.
J Chromatogr A. 2010 Apr 30;1217(18):3026-37. doi: 10.1016/j.chroma.2010.02.051. Epub 2010 Mar 1.
A new chromatographic method to determine the octanol-water partition coefficient (logP(o/w)) of organic substances is proposed in this paper. This method is based on a previously reported model that relates the retention factor in reversed-phase liquid chromatography with solute (p), mobile phase (P(m)(N)) and stationary phase (P(s)(N)) polarity parameters: logk=(logk)(0)+p(P(m)(N)-P(s)(N)). P(m)(N) values are calculated through expressions that depend only on the organic solvent fraction in the mobile phase. (logk)(0) and P(s)(N) parameters are characteristic of the chromatographic system and are determined from the retention of a selected set of 12 compounds. Then, the p value of a solute determined in a properly characterized system is easily derived from the retention factor data. Solute p values are slightly dependent on the chromatographic system but they are linearly related to those obtained in the reference system (Spherisorb ODS-2 column and acetonitrile as organic modifier). Therefore, they can be easily transferred from any experimental system to the reference one. A Quantitative Structure-Property Relationship study reveals that the p parameter in the reference chromatographic system depends, mainly, on the hydrophobicity of the compound, expressed as the n-octanol/water partition coefficient (logP(o/w)), and five additional structural descriptors which can be easily calculated through the CODESSA program from the chemical structure of the solute. In this work the p descriptors of a wide set of structurally different organic compounds have been determined in several chromatographic systems and transferred to the reference one from these and the CODESSA structural parameters. The logP(o/w) values have been determined. The obtained values agree with those determined from classical experimental techniques and validate the new method as a useful tool to determine the hydrophobicity of a wide variety of compounds in a broad logP(o/w) range.
本文提出了一种新的色谱方法来测定有机物质的辛醇-水分配系数（logP(o/w))。该方法基于先前报道的模型，该模型将反相液相色谱中的保留因子与溶质（p）、流动相（P(m)(N))和固定相（P(s)(N))极性参数联系起来：logk=(logk)(0)+p(P(m)(N)-P(s)(N))。P(m)(N)值通过仅依赖于流动相有机溶剂分数的表达式来计算。(logk)(0)和 P(s)(N)参数是色谱系统的特征，由选定的 12 种化合物的保留值确定。然后，从保留因子数据中很容易推导出溶质的 p 值。溶质的 p 值稍依赖于色谱系统，但与参考系统（Spherisorb ODS-2 柱和乙腈作为有机溶剂改性剂）获得的 p 值呈线性相关。因此，它们可以很容易地从任何实验系统转移到参考系统。定量结构-性质关系研究表明，参考色谱系统中的 p 参数主要取决于化合物的疏水性，用正辛醇/水分配系数（logP(o/w))表示，以及通过 CODESSA 程序从溶质化学结构计算的另外五个结构描述符。在这项工作中，在几个色谱系统中测定了广泛的结构不同的有机化合物的 p 描述符，并从这些系统和 CODESSA 结构参数转移到参考系统。测定了 logP(o/w)值。所得值与从经典实验技术确定的值一致，验证了新方法作为测定广泛范围内各种化合物疏水性的有用工具。
