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I am on Bruker 400

 


 

 

I am doing...

First things to do


Locking


Tuning


Shimming


Making a new experiment in the workspace


Proton 1D


Carbon 1D


Complex NMR experiments: 2D, selective, etc. (separate HTML page)



Using Temperature Control

Current Temperature Calibrations


Data Processing


DOSY


Finishing my work


Known glitches of Bruker 400 in Stepan


Solvent reference data


 

Troubleshooting

 

 

 



   YOU CAN DO THE ACTIONS LISTED BELOW ONLY IF YOU WERE DIRECTLY INSTRUCTED BY NMR CENTER STAFF !!!

 

Restarting spectrometer


Restarting the sample changer

 

 

 

 

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First things to do

1. Log in

2. Insert your sample

 

 

 

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Locking

At this point, your sample is the probe.

  1. Load the default shimset
  2. Issue: lock
  3. Select your solvent in the dialog window

Wait for the lock system to finish locking (see the status messages)

 

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Tuning

NOTE: If your solvent is toluene-d8 (Tol) and 'atma' fails with an error, follow these instructions: System will not tune when lock solvent is toluene-d8


Tuning system needs to know what nucleus you are going to work with. Follow these steps:

Automatic Tuning

Manual Tuning

Manual tuning mode allows you to see what channels are tuned, inspect the result of tuning and adjust if necessary

Probe is now tuned and ready for experiments.


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Shimming

Shimming is required to achieve good resolution in NMR spectra.

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Proton 1D

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Carbon 1D

 

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Using Temperature Control

IMPORTANT NOTE: If you need to use temperature OUTSIDE of 20-40 Deg C range,
you must be trained on the "Variable Temperature" protocol: contact NMR center staff to schedule training.

For all Variable Temperature tutorials and instructions see Variable-temperature NMR operation

 

The instrument is equipped with manual BCU-1 refrigerated chiller and liquid N2 chiller.

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Current Temperature Calibrations on Stepan 400

These calibrations were obtained 7/15-16/2020 for 400 MHz Bruker probe (Z108618_0557) on Stepan 400 by EK.

Stepan 400: Overview (see zoomed regions next)



Stepan 400: Low-temperature branch (obtained with LN2 chiller)

 

 

Stepan 400: Same data for extrapolation

 

 

Stepan 400: Low-temperature kink on a curve (no-trust region)

Stepan 400: Mid-range region

Stepan 400: High-temperature kink on a curve (no-trust region)

Stepan 400: High-temperature branch

IMPORTANT: Make sure that your LN2 chiller is disconnected and BCU-1 is in "Flush" mode!



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Data Processing

 

Calibrating the chemical shift axis using a reference spectrum in 1D

 

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DOSY Experiments

For detailed protocol see  DOSY on Bruker 400 and 500

 

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Finishing my work


 

 

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Known glitches of Bruker 400 in Stepan

Probe cannot tune. ATMA error "Channel cannot be wobbled with this probe (Probe [1H] cannot be selected on [1H] channel)

Sometimes ATMA will fail with a nonsensical message saying that "1H cannot be tuned on 1H channel". This is a glitch we are working with Bruker on resolving. It appears to happen at all times when the lock solvent is Tol, but may happen with other solvents too. Current workaround is this as follows. Any time you need to issue atma, you have to

For example, the following is a basic sequence of commands for NMR acquisition with Tol (note how atma is flanked by lock commands):

  1. rsh
    - select 'bbfo-latest'
  2. lock Tol
  3. lock off
  4. atma
  5. lock Tol
  6. topshim
  7. rga
  8. zg

 

 

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YOU DO THIS ONLY IF YOU WERE DIRECTLY INSTRUCTED BY NMR CENTER STAFF !!!

    Restarting spectrometer


 

To restart the Bruker 400 MHz system, follow these steps:

  1. Restart the workstation:
    1. Terminate Topspin
    2. Log out
    3. Choose "Restart" to reboot the computer
  2. Open the spectrometer cabinet (pull and turn the handle)



  3. Locate all system switches according to this picture:


       

  4. Side view of the console with the red reset button and Post Code display:





  5. Turn off power to the NMR system
    1. AQS3 - push red button, flip power switch to OFF (see the image above)
    2. Amplifiers: turn power OFF
    3. BSMS: turn power OFF
    4. turn Main Power Switch: OFF (push in red section)
    5. Ignore
  6. IMPORTANT: Eject current sample with 'sx ej'. If changer does not respond, you still proceed with next steps.

  7. Wait till the computer workstation boots up and reaches the login screen
  8. Boot up the NMR system
    1. Turn Main Power switch: ON (push in green section)
    2. Turn AQS3 power: ON
    3. wait for 1 minute to see the Post Code display increase the code from zero to around 94-98 (exact value does not matter)
    4. Turn Amplifier power: ON
    5. Turn BSMS power: ON
    6. Turn Sample Express power: ON (push the button on the front of the sample changer)
    7. wait for 1-2 minutes for all errors on amplifier and BSMS to clear and for the Sample Express to finish initialization and turn on a green light (sample will be ejected and re-inserted automatically).
    8. close the spectrometer cabinet
  9. Login to the workstation
  10. launch Topspin
  11. join a proton experiment
  12. issue "ii restart"
    (ignore the "status line active" message)
  13. Load a standard shimset: "rsh bbfo-latest"
  14. Proceed with locking (CDCl3)
  15. join experiment with proton and carbon and issue "atma"
    NOTE: Startup of atm module takes long time (3-5 minutes) but it continually outputs messages in the status line indicating it is not just frozen.
  16. issue "topshim "
  17. adjust gain: issue 'rga'
  18. Run test 1D 1H on CDCl3 standard: you should see undeuterated trace CHCl3 in one scan.


    At this point, spectrometer is ready for use.

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   Restarting the sample changer

 

For instructions on resetting SampleCase, please, see SampleCase tutorial

 

 

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