Position-specific 15 N isotope analysis in organic molecules : A high-precision 15 N NMR method to determine the intramolecular 15 N isotope composition and fractionation at natural abundance
© 2019 John Wiley & Sons, Ltd.
| Veröffentlicht in: | Magnetic resonance in chemistry : MRC. - 1985. - 57(2019), 12 vom: 01. Dez., Seite 1136-1142 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2019
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| Zugriff auf das übergeordnete Werk: | Magnetic resonance in chemistry : MRC |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't 15N INEPT 15N NMR 15N enrichment factor 15N isotopic profiling position-specific 15N isotope analysis |
| Zusammenfassung: | © 2019 John Wiley & Sons, Ltd. The position-specific 15 N isotope content in organic molecules, at natural abundance, is for the first time determined by using a quantitative methodology based on 15 N Nuclear Magnetic Resonance (NMR) spectrometry. 15 N NMR spectra are obtained by using an adiabatic "Full-Spectrum" INEPT sequence in order to make possible 15 N NMR experiments with a high signal-to-noise ratio (>500), to reach a precision with a standard deviation below 1‰ (0.1%). This level of precision is required for observing small changes in 15 N content associated to 15 N isotope effects. As an illustration, the measurement of an isotopic enrichment factor ε for each 15 N isotopomer is presented for 1-methylimidazole induced during a separation process on a silica column. The precision expressed as the long-term repeatability of the methodology is good enough to evaluate small changes in the 15 N isotope contents for a given isotopomer. As observed for 13 C, inverse and normal 15 N isotope effects occur concomitantly, giving access to new information on the origin of the 15 N isotope effects, not detectable by other techniques such as isotope ratio measured by Mass Spectrometry for which bulk (average) values are obtained |
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| Beschreibung: | Date Completed 21.11.2019 Date Revised 08.01.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1097-458X |
| DOI: | 10.1002/mrc.4903 |