Revision history - NMR Wiki Q&A Forum

1

initial version

posted Apr 08 '10 at 08:33

Well, you just need to reference the spectrum - they cannot always be automatically referenced. On older systems with `vnmr` software you'd type `wft ds`, then put the cursor on the reference peak (`CD2H` in your case), hit `ref` button and type in the chemical shift from the table. Also you might want to check the `solvent` parameter - it does affect referencing.

2

No.1 Revision

posted Apr 08 '10 at 08:48

Evgeny Fadeev
577●1

Well, you just need to reference the spectrum - they cannot always be automatically ~~referenced.~~referenced (an actually most of the time you need to enter a small correction manually)

On older systems with vnmr software you'd type wft ds, then put the cursor on the reference peak (CD2H in your case), hit ref button and type in the chemical shift from the table.

Also you might want to check the solvent parameter - it does affect ~~referencing.~~referencing. Just type solvent?. However in the end it's referencing what really matters, setting solvent parameter correctly may get you into the approximate range of correct referencing, but you'll still have to fix it up.

3

No.2 Revision

posted Apr 12 '10 at 09:14

Evgeny Fadeev
577●1

Well, you just need to reference the spectrum - they cannot always be automatically referenced (an actually most of the time you need to enter a small correction manually)

On older systems with vnmr software you'd type wft ds, then put the cursor on the reference peak (CD2H in your case), hit ref button and type in the chemical shift from the table.

Also you might want to check the solvent parameter - it does affect referencing. Just type solvent?. However in the end it's referencing what really matters, setting solvent parameter correctly may get you into the approximate range of correct referencing, but you'll still have to fix it ~~up.~~up - especially if you have a mixed solvent.

4

No.3 Revision

posted Apr 12 '10 at 15:08

Evgeny Fadeev
577●1

Well, you just need to reference the spectrum - they cannot always be automatically referenced (an actually most of the time you need to enter a small correction manually)

On older systems with vnmr software you'd type wft ds, then put the cursor on the reference peak (CD2H in your case), hit ref button and type in the chemical shift from the table.

Also you might want to check the solvent parameter - it does affect referencing. Just type solvent?. However in the end it's referencing what really matters, setting solvent parameter correctly may get you into the approximate range of correct referencing, but you'll still have to fix it up - especially if you have a mixed solvent.

edit: actually, I've missed an important point - if the transmitter frequency is set outside the "spectral window" of your compound - let's say just outside one of the edges of the spectrum (say left) - then some peaks from near the right edge will fold over and will show up at the left of your measured spectrum. To check if you have this situation - double the spectral window and see if any peaks move. If they do - move transmitter frequency to the middle of your spectrum.