University of Ottawa NMR Facility Web Site

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Monday, May 12, 2008

17O NMR for H2O vs. D2O

D2O rather than H2O is recommended for setting up an NMR spectrometer to observe 17O. This is because D2O is isolated based on its higher mass. It has more than the natural abundance of 17O and in turn gives a larger NMR signal than H2O which has only the natural abundance of 17O (0.037 %). The figure below shows the 17O NMR spectra of H2O and D2O acquired on the same volume of sample under identical conditions.


James said...

Glen, J coupling to the hydrogen isotopes with 17O? James

Glenn Facey said...

I suspect that the 1J coupling (~85 Hz) is not observed due to fast inter-molecular proton exchange.