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I am on Varian 600


 

Preparation of the spectrometer

Tuning

Locking

Gradient Shimming

Making a new experiment in the workspace

Proton and carbon 1D

2D experiments and other exciting stuff

Saving my data

Finishing my work

Importing and processing NMR data to Topspin

Restarting VT/Gas control

Solvent reference data

 

 

 

Specialized procedures (require separate training!)

Using variable temperature

Restarting spectrometer (only by authorized users!)

Turning on the spectrometer after a power outage (only by authorized users!)

Restoring cable contact for carbon tuning (only by authorized users!)

 

 

 

 

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Preparation of the spectrometer

 

1. Verify functional state of the Air supply and VT module

As you walk into the room: check that variable temperature and air supply modules are functional. Your standard operation temperature will be 25 Deg C. For using other temperatures see Using variable temperature section.

  1. Find Air supply and VT module in the room:



  2. The VT module contains the FTS Systems control box  sitting on top of the AirJet.


    • First, check that the AirJet is OFF. If - not, then press the green switch to turn it off.

    • The FTS module on top has a display. If green "RUN" is lit, press white "RUN" button once to turn it off:


NOTE: If you don't see normal gas flow value of about 12 L/min, you need to restart VT and air supply system. See: Restarting VT/Gas control


At this point, the VT module and Air supply (Pneumatics) are in a correct state.


 

2. Start temperature control through VNMRJ

3. Insert sample in the spinner

4. Insert sample in the magnet

Your sample and spectrometer are ready for tuning, locking, and shimming.

 

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Tuning

Tuning may be done in any workspace. I recommend assigning the workspace #1 just for tuning

 

Broadband channel

High-frequency channel: 1H or 19F

Here is a view of a tuned probe with 3 MHz Span




NOTE: If the carbon profile is not looking symmetrical (above), this means the cable contact in the console is not good. Follow these steps to try to restore contact: Restoring cable contact for carbon tuning

 

Finishing Tuning

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Locking

Manual lock adjustment

 

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Gradient Shimming

You must shim every new sample and also re-shim if you changed temperature or did a very long acquisition (>3 hours).

NOTE 2: You must have a good lock level (>20) to for success of gradient shimming! If your lock level is very low, verify that you

  1. have lock solvent in your sample
  2. loaded good previous shims
  3. went through manual locking procedure to adjust z0 and phase
  4. verified that lock is not saturated - adjust power and phase (see Locking)

 

I recommend performing shimming in a dedicated workspace: #3

How to understand the Gradient Shimming output:


  1. Note Iteration #1 starts with relatively high rms err of 13.17 (Hz)
  2. At Iteration #2, rms err was reduced by adjustment of z1-z4 shims
  3. Addition of z5 to adjustment increases rms err (temporarily)
  4. By Iteration #4, the rms err was reduced to 0.48, which is a good low value.


Important steps to complete the shimming:


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Making a new experiment in the workspace

 

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Proton and carbon 1D

 

Workflow for initial set up:

How to run an experiment with the same parameters as before

 

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2D experiments and other exciting stuff

To setup any complicated experiment :


 

More on 2D and other experiments

 

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Saving my data

Every experiment performed in the workspace must be explicitly saved to a vnmrsys/data. This is where the NMR server pulls your data from.

NOTE: At a later time, you may open any of saved files into any workspace to look at the data or run a new experiment. This will replace data in the workspace but the source file in the vnmrsys/data will not be affected.

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Finishing my work


Remember to save your data from every workspace where you did acqusition! See Saving my data

Insert a standard sample in the magnet

You are done with the Varian 600.

 

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Importing and processing NMR data to Topspin

 

Importing data

 

Processing a 2D Varian data in Topspin

For experiments performed with States-TPPI frequency discrimination mode (most common experiments):

  • Set ACQUPARS:Experiment section: FnMode = States
  • Set PROCPARS:Fourier Transform section, MC2 = States
  • Click Process

If the 2D experiment was performed with Rance-Kay (Echo-Antiecho) mode, then you should choose this mode for both settings above.

 

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Using variable temperature


IMPORTANT NOTE 1: Only change temperature in steps of 10 degrees followed by 3 minutes wait time after every step.


IMPORTANT NOTE 2: Only change samples while you are within -80 to +80 Deg C. When above or below these limits: change temperature first to shift probe to the inside the limits then - change the sample.


Here is why: the probe contains expensive glass insert which is a double-walled evacuated insulator. Step-wise increase in temperature allows thermal stress to dissipate safely for the glass. Eject action passes a lot of room-temperature air through the probe - also stresses glass.




 

 

 

 

 


   Using the temperature HIGHER than a room temperature

 

 

Back to Using variable temperature

 


   Using the temperature LOWER than a room temperature with Air-Jet FTSSystems chiller

Back to Using variable temperature

 

 

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Restarting VT/Gas control

Go to Start tab, Spin/Temp page;

 

Reset air supply

      1. Click Start : Spin/Temp

        • Setting for the VT Air Flow should be 10 L/min

      2. click Reset Pneumatics

        • you should see the lights on the router stop flashing

        • Air flow  on the router gauge should be 10-12 L/min

Reset temperature controller

      1. Click Start : Spin/Temp

      2. click Reset VT

        • watch the screen of the VT display show PASS and return to temperature value

        • Message bar shows "This operation takes a moment"

        • wait for it to switch to  "Set hardware operation complete"

      3. Start temperature control

        1. Enter 24 (for 25C in the probe)

        2. click Regulate  Temp

          • you should hear a knocking sound of the pressure valves switching

          • NOTE: If you need a temperature below 20C you need to be trained to use FTS temperature control system! (see Using variable temperature)


 

 

 

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     Restarting spectrometer (only by authorized users!)

This is a procedure for complete reboot of the VNMRS system if you see some "weird" behavior. There are two versions of the sequence: Light and Full Reboot.

Light Reboot

Use as the first remedy. This procedure re-initiates communication between PC and the VNMRS system. Takes about 2-3 min.

  1. Save shims first in VnmrJ
    1. type svs
    2. give an easy-to-remember file name:  current
      1. type 'y' if file exists
  2. Exit VnmrJ
  3. Stop communication with the console
    1. Open a terminal window (right-click on the screen desktop background, choose "Open Terminal")
    2. Type in su acqproc
    3. Wait till you see the command line prompt again
    4. type su acqproc again to start communication of the desktop computer with the console
  4. Start VnmrJ
    • you should see green status bar with "Idle" in it.
    • If you see a yellow bar with "Inactive" - stop and report a problem to NMR Center staff!
  5. Load shims
    1. type rts
    2. type the file name: current
    3. type su

You may proceed with locking/tuning/shimming, etc.


 

 

Full Reboot

Use this procedure if the Light Reboot sequence did not help.

  1. Save shims first in VnmrJ
    1. type svs
    2. give an easy-to-remember file name:  current
      1. type 'y' if file exists
  2. Exit VnmrJ
  3. Stop communication with the console
    1. Open a terminal window (right-click on the screen desktop background, choose "Open Terminal")
    2. Type in su acqproc
    3. Wait till you see the command line prompt again
  4. Log out of your account (this step may be skipped if no abnormalities to computer operation is observed)

    At this point you may also reboot the PC. It will create a completely clean state of the system.
  5. Log in
  6. Restart VNMRS system
    1. Push the reset button on the right-most board (labeled MASTER)
    2. Wait till the console restarts - the lights begin flashing again
      • you will hear a hiss at the pneumatic router and see flashing LEDS - normal!
  7. Start communication of the desktop computer with the console
    1. open the terminal window
    2. type su acqproc
    3. wait till the operation finished (you see new UNIX prompt)
  8. Start VnmrJ
    • you should see green status bar with "Idle" in it.
    • If you see a yellow bar with "Inactive" - stop and report a problem to NMR Center staff!
  9. Load shims
    1. type rts
    2. type the file name: current
    3. type su
  10. Reset air supply
    1. Click Start : Spin/Temp
      • Setting for the VT Air Flow should be 10 L/min
    2. click Reset Pneumatic Router
      • you should see the lights on the router stop flashing
      • Air flow  on the router gauge should be 10-12 L/min
  11. Reset temperature controller
    1. Click Start : Spin/Temp
    2. click Reset VT Controller
      • watch the screen of the VT display show PASS and return to temperature value
      • Message bar shows "This operation takes a moment"
      • wait for it to switch to  "Set hardware operation complete"
    3. Start temperature control
      1. Enter desired value
      2. click Regulate  Temp
        • you should hear a knocking sound of the pressure valves switching
        • NOTE: If you need a temperature below 20C you need to be trained to use FTS temperature control system!


  12. Turn on spinner (if needed)
    NOTE: Spinning on this machine is not stable and not recommended.
    1. Set spin speed to 20 Hz
    2. click Regulate Speed
  13. wait 5 min to allow for all values to equilibrate
  14. you may proceed with locking/tuning/shimming, etc.

 

 

 

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Turning on the spectrometer after a power outage

If there was a power outage and the UPS did not hold for long enough, the spectrometer console shuts down and does NOT automatically restart after the power has been restored. You will find spectrometer console silent and VNMRJ will be showing "Inactive" in its status bar. If you open the right door of the console cabinet you will see no lights:

 

You will need to turn on spectrometer console, reconnect with VNMRJ and reset the VT gas supply. To do this:

    1. Exit VNMRJ
    2. Approach the back spectrometer console:






    3. Find "Main Power" switch and flip it down (if it was up) then flip it up. After that, push the green button to start the console.





    4. Check the startup of the console: open right door and look at the lights of the digital boards. Immediately after restart you may see only a few lights:



      which will change into a "dynamic display" of blinking lights running up and down -- similar on all boards:



      A this point, the console has been fully started.

    5. Close the console door
    6. Launch Topspin
    7. Follow this link to restart VT gas control:  Restarting VT/Gas control

 

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Restoring cable contact for carbon tuning

This procedure is due when the X-nucleus tuning curve in trtune('remotely') does not have a symmetrical shape like this (green):

When the console cable connection goes bad, the green curve would look very significantly lopsided or distorted. This leads to poor sensitivity on X channel.

Protocol to remedy the issue:

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