Török Roland, Berkecz Robert, Péter Antal
Department of Inorganic and Analytical Chemistry, University of Szeged, P.O. Box 440, H-6701 Szeged, Hungary.
J Chromatogr A. 2006 Jul 7;1120(1-2):61-8. doi: 10.1016/j.chroma.2005.11.098. Epub 2005 Dec 15.
The retention of enantiomers of chiral analytes, i.e. alpha-substituted glycine analogs, on a quinine-based anion-exchanger chiral stationary phase was studied in the temperature range of 5-70 degrees C and at different mobile phase compositions, using isocratic elution in the reversed-phase mode. By variation of both mobile phase composition and temperature, baseline separations could be achieved for these enantiomers. Separation could be optimized more quickly by adjusting the column temperature rather than the mobile phase composition. The dependence of the natural logarithms of retention and selectivity factors (lnk' and lnalpha) on the inverse of temperature, 1/T (van't Hoff plots) was used to determine thermodynamic data on the enantiomers. Calculated thermodynamic constants (Delta(DeltaH degrees ), Delta(DeltaS degrees ) and Delta(DeltaG degrees )) were applied to promote an understanding of the thermodynamic driving forces for retention in this chromatographic system. The elution sequence of the enantiomers in most cases was determined.
在手性固定相上，研究了手性分析物（即α-取代甘氨酸类似物）对映体在5至70摄氏度温度范围内以及不同流动相组成下的保留情况，采用反相模式等度洗脱。通过改变流动相组成和温度，这些对映体可实现基线分离。相较于调整流动相组成，调节柱温能更快地优化分离效果。利用保留因子和选择性因子的自然对数（lnk'和lnalpha）对温度倒数1/T的依赖性（范特霍夫曲线）来确定对映体的热力学数据。计算得到的热力学常数（Δ(ΔH°)、Δ(ΔS°)和Δ(ΔG°)）用于促进对该色谱系统中保留的热力学驱动力的理解。在大多数情况下，确定了对映体的洗脱顺序。
