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Topic: NMR Reference  (Read 2529 times)

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Offline HailoMan

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NMR Reference
« on: September 26, 2016, 12:49:52 AM »
Apology in advanced if this is a silly question, but in calibrating 1H NMR spectra, can I use water residue as a reference instead of the internal solvent residue?
I did a 1H NMR measurement of gamma-valerolactone (GVL) in DMSO-d6. The DMSO residue peak (2.50 ppm) happen to overlap with 2 of the proton peaks of GVL, so I can't use the DMSO as an internal standard.

Offline discodermolide

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Re: NMR Reference
« Reply #1 on: September 26, 2016, 06:03:33 AM »
Surely this compound should be soluble in chloroform? Then you can use that as the reference.
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Offline Babcock_Hall

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Re: NMR Reference
« Reply #2 on: September 26, 2016, 10:13:03 AM »
The chemical shift of water depends upon temperature; therefore, one would have to take this into account.

Offline HailoMan

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Re: NMR Reference
« Reply #3 on: September 28, 2016, 03:58:27 AM »
Surely this compound should be soluble in chloroform? Then you can use that as the reference.

Unfortunately, the compound (nitrogen-doped carbon nanotubes) is non-dispersible in chloroform or other common NMR solvents.

The chemical shift of water depends upon temperature; therefore, one would have to take this into account.

Thank you for this information. I will look into it.

Offline Dan

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Re: NMR Reference
« Reply #4 on: September 29, 2016, 04:44:23 AM »
Why not just add an internal reference that does not overlap with anything - e.g. tetramethylsilane at 0 ppm?
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