Practical Guide for Varian NMR Systems
- Make entry in NMR log book.
- Log into the console computer.
- At the console computer enter user name and password at the log in screen.
- Open NMR software by clicking on the Vnmr icon.
- Check aquisition status. If status is inactive, type: nmr500 or nmr400 <enter> depending on the system.
- To insert the NMR tube into the magnet read the follow description below.
Type e <enter> to eject the standard sample.
This causes a column of air within the bore of the magnet to lift the standard sample/spinner out of the magnet.
Replace the standard sample with your sample into the spinner.
Adjust sample position with the depth gauge.
Place the spinner with your sample on top of the magnet.
Type i <enter> to insert your sample into the magnet.
This causes the column of air to slowly decrease, allowing the sample to descend into the center of the magnet.
5. Retrieve shims.
Type callshim <enter> to retrieve the most current shim set for the magnet.
6. Select experiment type by clicking [Setup]
Then click on the appropriate experiment [H1, CDCl3], [C13, CDCl3] or [Nucleus, Solvent].
7. Locking on deuterated solvents.
Open the Acquisition dialog box by clicking on the [Acqi] button.
Click on the [LOCK] button.
The correct setting is dependent upon which and how much duterated solvent is within sample. A lock power value of 20 +/- 5 should be enough. Once lock resonance is found decrease power as much as you can while maintaining a good lock. Caution: Too much power could saturate your lock signal.
Begin with a high value of 35 +/-5 until lock resonance is found. Then decrease as much as you can when shims improve.
Ensure the LOCK: [off] button is selected.
Adjust the Z0 shim until the lock signal is on resonance. Once on resonance click the LOCK: [ON] button.
Adjust the lock phase for a maximum lock signal.
Set the spin rate to 20 (Hz) for improved radial (X,Y) shims.
8. Shimming the magnet.
In the acquisition dialog box, click on the [Acqi] button if not already open.
Click on the [SHIM] button.
Adjust Z1, Z2 for a maximum lock level.
9. Once locked and shimmed close the acquisition dialog box by clicking the [CLOSE] button.
10. Acquiring an NMR spectrum.
To begin the experiment type ga <enter>.
11. Saving NMR spectrum data.
To save data type svf <enter>. Then type filename <enter>.
12. Log out of Vnmr by typing exit <enter>.
13. Log out of console computer by clicking on the [EXIT] button.
Acknowledge log out confirmation by clicking the [OK] button.