Pages Guilhem, Delaurent Corinne, Caldarelli Stefano
JE 2421 TRACES, Universités de Provence et Paul Cézanne Aix-Marseille I et III, Site de Saint Jérôme, Case 512, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
Anal Chem. 2006 Jan 15;78(2):561-6. doi: 10.1021/ac051454n.
The diffusional properties of molecules in solution vary dramatically upon addition of a solid chromatographic phase. This effect can be monitored via pulsed-gradient spin-echo NMR used in conjunction with moderately fast rotation of the sample (high-resolution magic angle spinning) to produce exploitable spectra. The molecular diffusion coefficients observed in this condition are averages reflecting the equilibrium population distribution among the different phases. It is thus possible to use this information for investigating a crucial step of reversed-phase chromatography, namely, the partitioning of the analyte between different phases. In this work, we describe the evolution of the apparent diffusion coefficient of typical solutes for water/acetonitrile solvent mixtures of varying proportions.
在溶液中加入固体色谱相后，分子的扩散特性会发生显著变化。这种效应可以通过与样品适度快速旋转（高分辨率魔角旋转）结合使用的脉冲梯度自旋回波核磁共振来监测，以产生可利用的光谱。在这种条件下观察到的分子扩散系数是反映不同相之间平衡总体分布的平均值。因此，有可能利用这些信息来研究反相色谱的一个关键步骤，即分析物在不同相之间的分配。在这项工作中，我们描述了不同比例的水/乙腈溶剂混合物中典型溶质的表观扩散系数的变化情况。
