Size-exclusion chromatographic NMR under HR-MAS
| Autor: | Iain J. Day, Natalie Anderson, Guillermo Lucena Alcalde |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
chemistry.chemical_classification
Chromatography 010405 organic chemistry Rotor (electric) Sample (material) Size-exclusion chromatography Analytical chemistry General Chemistry Polymer 010402 general chemistry 01 natural sciences Magnetic susceptibility 0104 chemical sciences law.invention chemistry law Magic angle spinning General Materials Science Spectral resolution Diffusion (business) |
| Zdroj: | Magnetic Resonance in Chemistry. 55:485-491 |
| ISSN: | 0749-1581 |
| DOI: | 10.1002/mrc.4464 |
| Popis: | The addition of stationary phases or sample modifiers can be used to modify the separation achievable in the diffusion domain of diffusion NMR experiments or provide information on the nature of the analyte–sample modifier interaction. Unfortunately, the addition of insoluble chromatographic stationary phases can lead to line broadening and degradation in spectral resolution, largely because of differences in magnetic susceptibility between the sample and the stationary phase. High-resolution magic angle spinning (HR-MAS) techniques can be used to remove this broadening. Here, we attempt the application of HR-MAS to size-exclusion chromatographic NMR with limited success. Observed diffusion coefficients for polymer molecular weight reference standards are shown to be larger than those obtained on static samples. Further investigation reveals that under HR-MAS it is possible to obtain reasonably accurate estimates of diffusion coefficients, using either full rotor synchronisation or sophisticated pulse sequences. The requirement for restricting the sample to the centre of the MAS rotor to ensure homogeneous magnetic and RF fields is also tested. |
| Databáze: | OpenAIRE |
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