Basic Bruker C13 NMR Tutorial
Instrument Startup, Optimization, and Shutdown
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Note: if there is a sheet of paper attached to the monitor which says 'Experiment in Progress' or something similar, contact your laboratory instructor before proceeding.
Check the NMR Log Book! You must make an entry in the Log Book when you are operating
the NMR. Include the date, time, your name, where you're from and what sample you ran or
what you did on the instrument. If you find any problems with the instrument, note them there.
The Log Book is meant to record everything that gets run or done to the instrument, and is very
useful for tuning and maintenance purposes. It must be kept up to date.
INSTRUMENT LOG-ON:
Users must log-on to the system before running the NMR. After log-on, start the main NMR
program by typing 'xwinnmr' at a UNIX prompt. Load the experimental parameters you need by
typing 'rpar' at the Xwinnmr command prompt and selecting the experiment from the displayed
list. Experimental parameters will be chosen by your laboratory instructor and stored with a
unique name.
INSERTING THE SAMPLE INTO THE PROBE:
At the Xwinnmr command line, type 'mas' and press Enter. After the MAS window opens, click the 'Eject Sample' button. When the lift air is heard, open the sample loading door on top of the sample guide and remove the sample spinner, if necessary.
After the lift air stops, hold your spinner vertically with the cap up and drop it into the probe. Close the door on the sample loading guide.
In the MAS window, click the 'Insert Sample' button. When the lift air stops, you should hear the Magic Angle stator click into position.
If you have problems, get your laboratory instructor to help you.
SAMPLE SPINNING:
The spin rate for your experiment will be selected by your laboratory instructor. If not, enter
3000 into the 'Spin Rate:' field and press Enter. Click the 'Spinning: Off' button and select 'On'
from the menu. Click the 'ContinuousUpdate' button to monitor the spin rate. The spinning rate
should reach 3000 Hz in a minute or so. After it does, click the 'Cancel' button in the MAS
window.
If the 'Actual' spin rate does not reach 3000 Hz after a minute or so, or you hear whirring noises coming from the probe, you've got a problem. Get your laboratory instructor to help you.
Open the right cabinet door on the NMR console and look at the MAS pneumatic unit display. If you see an error message saying 'USE MANUAL MODE' then click the 'Spinning: Off' button in the MAS window and choose 'Off' from the menu.
After the sample stops spinning, click the 'Eject Sample' button. When the lift air is heard, open the sample loading door on top of the sample guide and remove the sample spinner. Close the door on the sample loading guide.
You need to repack this sample.
INSTRUMENT OPTIMIZATION:
At the Xwinnmr command line, type 'wobb' and press Enter. Now type 'acqu' and press Enter. This initiates the probe tuning mode and switches to the acquisition screen so you can see the tuning signal in real time.
The tuning signal should be sharp and centered on the reference line in the center of the screen. If not, you'll need to tune the probe for your sample. If the probe needs tuning, get help from your laboratory instructor.
At the Xwinnmr command line, type 'stop' to exit probe tuning mode.
CHECK THE SHIM SETTINGS
This section is not yet complete...
REMOVING THE SAMPLE FROM THE PROBE:
At the Xwinnmr command line, type 'mas' and press Enter. After the MAS window opens, click the 'Spinning: Off' button and select 'Off' from the menu. Click the 'ContinuousUpdate' button to monitor the spinning rate.
After the sample stops spinning, click the 'Eject Sample' button. When the lift air is heard, open the sample loading door on top of the sample guide and remove the sample spinner. Close the door on the sample loading guide.
Click the 'Cancel' button in the MAS window.
If you have problems, get your laboratory instructor to help you.
PROGRAM SHUTDOWN AND LOG-OFF
If the MAS window is open, click the 'Cancel' button to close it.
Click on the Xwinnmr 'File' menu and choose 'Exit'. Click 'OK'.
Click on the 'Desktop' menu and choose 'Logout'. Click 'Yes' to log-out.