NMR Operations for QE 300 (brief)

For more details about these directions see QE 300 operation (detailed).


Typographic Conventions:

  1. Special keys are written out, press the key shown, ie: <return> means to press the key that says "return".

  2. Most commands are entered as 2 letter commands. These commands are represented here as bold caps in brackets ie [EJ]. They are entered without a <return>.

  3. Some sequences require holding the control key and pressing an additional key. [^W] means hold the <control> key and press W.

  4. Additional comments are made in italics.

  5. A sequence of keystrokes or commands is separated by commas.


Safety:

  1. DO NOT ENTER KB 421 if you have a pacemaker or other metal implant.

  2. DO NOT place any magnetic material near the magnet.

  3. DO NOT drop small metal material in the room.

  4. DO NOT bring large metal objects into KB 421.

  5. Credit Cards, Computer Disketts, and ATM cards can be erased inside the yellow warning rope.

  6. DO NOT work unsupervised

  7. Follow Directions and Ask questions. The NMR costs about $150,000, be careful

  8. Sign-in the logbook


Sample Preparation:

  1. Use the high-quality 8" NMR tubes

  2. Add Sample to the tube
    1. For liquid samples use a couple drops of sample in the NMR tube
    2. For solid samples add a couple microspatula tips

  3. Add an appropriate solvent to a height of 4 cm (Use the sample holder)

  4. Wipe the outside of the tube with a clean Kimwipe.

  5. DO NOT GET FINGERPRINTS INTO THE NMR.


Sample Loading:

  1. Eject the current sample from the NMR. [EJ]

  2. Remove the sample (DO NOT TOUCH THE SPINNER).

  3. Place the spinner on your sample tube and set the spinner height with the gauge.

  4. Wipe any fingerprints off of the NMR tube with a Kimwipe.

  5. Place the tube (WITH THE SPINNER) on the stack.

  6. Lower the sample into the the NMR. <return>

  7. Place the Plastic Cap on the top of the Stack.

  8. The Spin (top center of monitor) should read 15 or 16 (use AA to adjust).


Setup the Magnet For The New Sample

  1. Select the solvent for Deuterium Lock. [NS]

  2. Setup the Deuterium Lock. [LD]
    1. Set the Transmitter Gain. [T]
      1. 200 for CDCl3
      2. 125 for D-6 Acetone
    2. Toggle to the sweep display. [S]
    3. Center the peak by changing the offset. [O] (then use knob to adjust)
    4. Toggle to the meter display. [S]
    5. Set to Lock Fast Mode. [L] (press until "Lock Fast" is selected)
    6. Set the Gain. [G] (use knob to adjust signal to 70)
    7. Set to Lock Slow. [L] (press until "Lock Slow" is selected)
    8. Exit Lock Display. <return>

  3. Shim the Magnetic Field. Execute the Shim Macro. [XM], 64, <return>, Y, <return>

  4. Return to the Lock Display and reset the gain to 70. [LD], [G], (---)


Setup Computer for New Experiment

  1. Select the Current Nucleus. [CN]

  2. Set the Reciever Gain. [SG]

  3. Set the Number of Acquisitions (start with 8 for 1-H, 64 for 13-C). [NA]

  4. Set the Block Size (suggest 16k for 1-H, 32k for 13-C). [CB]

  5. Parameters for special pulse sequences (Optional)
    1. Select the Pulse Sequence. [EX]
    2. Setup the Decoupler.
      1. Select Frequency (ppm). [F2]
      2. Select Power (attenuation, start with 2800). [L1]
      3. Turn On and select modulation. [DN]
        1. #2 for broadband decoupling
        2. #4 for selective decoupling

  6. Changes to standard conditions (Optional)
    1. For optimum S/N;
      1. Determine T1, T2*, and spectral window.
      2. Set Recycle Delay to 0 sec. [D5]
      3. Set the aquisition time so D2 > 3 T*2 . [CB]
      4. Set pulse to Ernst angle (From graph of acquisition time [AT] and T1). [P2].

    2. For optimum integration;
      1. Determine T1, T2*, and spectral window.
      2. Set Spectral Window to area of interest.
      3. Set Acquisition Time to 3 T*2 by adjusting block size. [CB]
      4. Set tip angle to π/2, [P2], 90D,
      5. Set Recycle Delay [D5] so Acquisition Time [AT] is 5T1
      6. Collect Data. [ZG]
      7. Save Data. [SA]
      8. Run Gossip on PC then [SE] to transfer file to PC.

Process the FID

  1. Baseline Correct FID. [BC]

  2. Optional processing to enhance FID.
    1. Zero Fill FID (improve digital resolution if needed). [ZF]
    2. Apodize FID with Line Broadening Factor. [LB] (optional, select one)
      1. Exponential Multipliction (improve S/N). [EM]
      2. Double Exponential Multiplication (improve resolution). [DM]
      3. Gaussian Multiplication (improve resolution). [GM]

  3. Fourier Transform FID. [FT]


Process the Spectrum

  1. Phase the Spectrum
    1. Autophase. [AP]
    2. Phase to previous settings. [PS]

  2. Set TMS to 0.0 ppm
    1. Zoom on TMS. [ZO]
    2. Select region with knob or cursor and arrow keys.
    3. Expand zoom region. [^E]
    4. Autoscale Y-Axis [^Y]
    5. Select the TMS Peak. [P]
    6. Reset the origin. [O], [0P], <return> (Offset, Zero, Peak)
    7. Return to full spectrum [^F]

  3. Plot the spectrum
    1. Place two pens in carriage
    2. Autoscale spectrum. [YS]
    3. Plot Spectrum. [PL]
    4. Label Spectrum. [LC]
    5. If finished advance to next page. [NP]

  4. Integrate (Not used for 13-C, unless followed intructions to optimize integration).
    1. Switch to Integration Display. [ID]
    2. Scale the Integration
      1. Increase. [I]
      2. Decrease. [D]
    3. Adjust the Integration
      1. Slope. <right> and adjust with knob
      2. Curvature. <up> and adjust with knob
    4. Plot Integral [P]
    5. Advance Plotter to next page. [NP]


Transfer Files using Gossip

  1. Run Gossip on PC
  2. From NMR use [SE] to send current data set to PC
  3. From PC use Gossip to download file by name


Cleanup

  1. Remove pens from plotter

  2. Switch to 1-H acquisition and default parameters. [CN], [P^D]

  3. Remove your sample. [EJ]

  4. Replace line shape sample. <return>

  5. Replace Plastic Cap.

  6. Change Solvent for lineshape sample (D-6 Acetone). [NS]

  7. Lock on line shape sample. [LD]

  8. Shim magnet. [XM], 64, <return>

  9. Turn Monitor Off.

  10. Turn Plotter Off.

  11. Signout Logbook.


This page is maintained by
Scott Van Bramer
Department of Chemistry
Widener University
Chester, PA 19013

Please send any comments, corrections, or suggestions to svanbram@science.widener.edu.

This page has been accessed 1326 times since 1/5 /96 .
Last Updated 1/5/96