Institute of Chemistry, Edmond J. Safra Campus, Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
J Magn Reson. 2012 Jul;220:18-25. doi: 10.1016/j.jmr.2012.05.002. Epub 2012 May 14.
The NMR chromatography method is applied to a class of molecules with similar physical properties. We correlate the separation ability of microemulsions to the physical properties of the analyzed molecules. Flavor and aroma compounds are very widespread. Compositional analysis is in many cases tedious. Any new method of analysis is always useful and challenging. Here we show a new application to a class of fragrance molecules, with only a moderate variation in their chemical and physical characteristics. Up to 11 selected compounds in one mixture are resolved in one spectrum by NMR chromatography, despite the similarity of the compounds. The differences between O/W and W/O microemulsions and their resolution mechanism as applied to fragrance molecules are explained in terms of hydrophilicity and lipophilicity and effective critical packing parameters of the microemulsions. The observed diffusion rates are shown to correlate with solvation parameters. These results can be used to estimate the diffusion rates of molecules to be separated, allowing selection of the microemulsion or NMR chromatography solvent appropriate for each specific application.
NMR 色谱法适用于一类具有相似物理性质的分子。我们将微乳液的分离能力与被分析分子的物理性质相关联。风味和香气化合物非常广泛。在许多情况下，成分分析很繁琐。任何新的分析方法总是有用且具有挑战性的。在这里，我们展示了一种新的应用，即对一类具有化学和物理特性中等变化的香料分子。通过 NMR 色谱法，在一个混合物中可以在一个光谱中分辨出多达 11 种选定的化合物，尽管这些化合物具有相似性。O/W 和 W/O 微乳液之间的差异及其对香料分子的分辨率机制是根据亲水性和疏水性以及微乳液的有效临界堆积参数来解释的。观察到的扩散速率与溶剂化参数相关。这些结果可用于估计待分离分子的扩散速率，从而选择适用于每种特定应用的微乳液或 NMR 色谱溶剂。
