Zielinski Matthew E, Morris Kevin F
Department of Chemistry, Carthage College, 2001 Alford Park Drive, Kenosha, WI 53140, USA.
Magn Reson Chem. 2009 Jan;47(1):53-6. doi: 10.1002/mrc.2348.
Diffusion-ordered NMR spectroscopy resolves mixture components on the basis of differences in their respective diffusion coefficients or molecular sizes. However, when components have near-identical diffusion coefficients, they are not resolved in the diffusion dimension of a diffusion-ordered spectroscopy (DOSY) spectrum. Adding surfactant micelles to these mixtures has been shown to enhance resolution when the component molecules interact differentially with the micelles. This approach is similar to that used in electrokinetic chromatography (EKC) where modifiers like micelles or polymers are used to enhance the separation of mixture components. In this study, perdeuterated surfactants are added to analyte mixtures studied with the DOSY technique. Since no micelle resonances appear in the mixture spectra, the difficulty associated with performing biexponential analyses in spectral regions where analyte and surfactant resonances overlap is avoided. The approach is demonstrated using mixtures of peptides with near-identical diffusion coefficients.
扩散排序核磁共振光谱法根据混合物各组分各自的扩散系数或分子大小差异来分辨各组分。然而，当各组分的扩散系数近乎相同时，它们在扩散排序光谱法（DOSY）谱图的扩散维度中无法被分辨出来。已表明，当组分分子与表面活性剂胶束有不同的相互作用时，向这些混合物中添加表面活性剂胶束可提高分辨率。这种方法类似于电动色谱法（EKC）中所使用的方法，在电动色谱法中，诸如胶束或聚合物之类的改性剂被用于增强混合物各组分的分离。在本研究中，将全氘代表面活性剂添加到用DOSY技术研究的分析物混合物中。由于在混合物谱图中未出现胶束共振，避免了在分析物和表面活性剂共振重叠的光谱区域进行双指数分析时所面临的困难。使用具有近乎相同扩散系数的肽混合物来演示该方法。
