Moldoveanu Serban, David Victor
R.J. Reynolds Tobacco Co., Winston-Salem, NC, USA.
Faculty of Chemistry, University of Bucharest, Romania.
J Chromatogr A. 2015 Feb 13;1381:194-201. doi: 10.1016/j.chroma.2015.01.034. Epub 2015 Jan 16.
Phase ratio Φ for an HPLC column is a common parameter being defined as the ratio between the volume of the stationary phase V(st) and the void volume of the column V0. Although apparently simple, the evaluation of phase ratio presents difficulties because there is no sharp boundary between the mobile phase and the stationary phase, and different mobile phases lead to different "effective" phase ratios. A considerable number of studies have been dedicated to the evaluation of V(st) and V0 with the goal of obtaining the value for Φ. However, the parameter is seldom reported for common commercially available columns and key information for its calculation (e.g. the weight of column packing) is not typically reported by the vendors. Present study describes a novel procedure for the evaluation of phase ratio for a chromatographic column when used with a given mobile phase. The procedure allows the calculation of Φ only from the measurements of retention factors k' for two hydrocarbons i and j, for which the octanol/water partition coefficients log K(ow) are known. A theoretical support for this procedure based on solvophobic theory of interactions in solution is presented, and several experimental results reported in the literature are used to demonstrate the validity of the procedure.
高效液相色谱（HPLC）柱的相比率Φ是一个常用参数，定义为固定相体积V(st)与柱的死体积V0之比。尽管相比率的定义看似简单，但对其进行评估却存在困难，因为流动相和固定相之间没有明显的界限，而且不同的流动相会导致不同的“有效”相比率。为了获得Φ的值，大量研究致力于V(st)和V0的评估。然而，对于常见的市售色谱柱，该参数很少被报道，而且供应商通常也不会提供其计算所需的关键信息（例如柱填料的重量）。本研究描述了一种用于评估色谱柱在使用特定流动相时相比率的新方法。该方法仅通过测量两种已知正辛醇/水分配系数log K(ow)的烃类i和j的保留因子k'，就能计算出Φ。本文基于溶液中疏溶剂相互作用理论为该方法提供了理论支持，并引用了文献中报道的几个实验结果来证明该方法的有效性。
