Deuterated solvent.typically used in NMR play several roles:
- Reducing Solvent signal, that otherwise may overwhelm sample signals
- internal calibration of ppm axis using shift of solvent signal
- Long term stability of field using deuterium Lock
- The topshim automatic shimming uses the deuterium signal of the solvent by default.
For samples with sufficient concentration regular solvents can be used, but the default procedure needs to be modified.
Running no-D spectra in automation is very straightforward. There are only two things to consider:
When selecting the solvent, chose the protonated version instead of the deuterated: For example, H2O instead of D2O, DMSO-H6 instead of DMSO, CH3OH instead of MeOD. This will autamatically do the following:
- Skip locking on a solvent (Turn off the lock)
- Use a topshim macro customized for proton without lock
Make sure that automatic calibration got a reasonable result, and manually calibrate using the solvent signal if necessary as described in the NMR long manual
In manual mode, the following modifications to the standard procedure are necessary:
- When creating the dataset, select the protonated version of your solvent off the list. If you forget, type solvent to set it afterwards.
- Type locknuc and set it to “OFF”
- Skip locking on a solvent
- Instead of clicking on [Shim] in the top flowbar, type lctshim on the command line or click on [No D shim] in the customized toolbar
- Adjusting receiver gain is essential
- Make sure that automatic calibration got a reasonable result, and manually calibrate using the solvent signal if necessary as described in the NMR long manual