Access to instruments

  • Instruments are accessible to anyone who has been trained on their use by the Nuclear Magnetic Resonance (NMR) laboratory staff and who has a current account.
    • No unauthorized training allowed.
  • We need to have a budget number (EFS string) on file to create your NMR account.
  • Each authorized user is given a six-letter login code and computer account for scheduling time on the instruments and for using the instruments.
    • Please use a secure password.
    • Do not let anyone else use your account.
      • Violators will lose access privileges for a one-week period.

After hours access via U-card

U-cards are activated on a weekly basis, usually on Thursday.

  • You must use a computer on the University network.
    • Complete this U-card form 
    • Only send the information once. 
    • If your U-card does not work, check with Letitia Yao in the Nuclear Magnetic Resonance laboratory.
  • If you are a newly-trained user of the Mass Spectrometry Laboratory or the X-Ray Crystallographic Laboratory, and you already have access to the Nuclear Magnetic Resonance laboratory, send an email to Letitia Yao,, to add your card number to the doors for those laboratories.
    • Do not resubmit your card number.

General policies

  • No food or beverages near the spectrometers or workstations.
  • Do not leave your NMR tubes in the laboratory.
  • If a sample breaks in the magnet, contact the NMR lab staff immediately so the probe can be cleaned.
    • This will minimize probe damage from corrosive solvents.
  • Repairs for any damage to the probes resulting from user error are charged to the user group.
  • All users must abide by the scheduling restrictions posted in the lab.
  • All VI-500 users must lock on the D2O dummy sample when finished with the spectrometer.
    • If the dummy sample breaks, contact the NMR lab staff so it can be replaced with an appropriate tube.
  • Non-standard experiments (VT work, exotic nuclei) must be scheduled one week in advance with the NMR lab staff.
  • Read the manuals.

Sample preparation

  • Do not use chipped or cracked NMR tubes.
  • Use 7" or 8" tubes. For the VI-300, 8" tubes are mandatory.
  • Use 507PP (300-400 MHz) or 528PP (500 MHz) NMR tubes on all the instruments to prevent damage to the probes.
    • The NMR lab does not provide solvents or other supplies for your use.
  • Standard shims on the Varian instruments are determined on a sample 50 mm in height (0.70 mL); for the Bruker instruments, 40 mm (0.55 mL).
    • Shorter samples require additional time to shim.
    • Longer samples waste solvent and dilute the concentration.

Variable temperature work

  • Separate training is required for variable temperature work.
  • For sample preparation, use no more than 0.45 mL of solvent.
  • Be aware of the temperature limitations on the probe you are using. If unsure, ask!!
  • Always use new 528 NMR tubes and the special VT spinner for VT work.
    • Old tubes may be scratched and more likely to break.
  • For variable temperature work, you must schedule enough instrument time to bring the temperature back to room temperature when you are finished.
    • On the AV-500, this is 300K; on the AM-400, this is 298K.

Use restrictions


  • See sign posted on the instrument for maximum allowable scans per experiment.


  • 1-hour limit during the daytime
  • 3-hours maximum during the nighttime


  • 1-hour limit during the daytime
  • 4-hours maximum during the nighttime

AM-400, VI-500, AV-500

  • Monday-Friday, 8 a.m. to 6 p.m.
    • 6 slots per user
    • can be reserved up to 24-hours in advance
  • Monday-Friday, 6 p.m. to 8 a.m., and weekends
    • unlimited slots

All spectrometers for nights and weekends

  • reserve 2 weeks in advance
  • Holidays: weekend restrictions in effect

Instrument time charges

Instrument usage is charged to your EFS string:

Instrument Hourly Rates
VI-300 $7.20 day/night/weekend
AM-400 $8.10 day, $4.05 night/weekend
AX-400 $8.10 day/night/weekend
VI-500/AV-500 $9.00 day, $4.50 night/weekend
HD-500 $9.00 day/night/weekend
  • night rates begin at 8 p.m. and end at 8 a.m.
  • Operator time is $60 per hour for any instruction, at all times.
  • You will be charged for any time that is scheduled, but not used.
    • Cancel any unused time.

Service work

  • Samples may be submitted to the NMR staff to run for you.

Archiving data

  • Data is saved to CD-ROM when data directories are full.
    • The CD-ROMs are loaded and constantly accessible through the [Main Menu] - [File] - [Oldfids] menu buttons.
    • For data older than this, the NMR lab staff can load the appropriate CD- ROM, then accessible through the [Special] menu option.


  • Mailing address
    Nuclear Magnetic Resonance Laboratory
    Department of Chemistry
    University of Minnesota
    207 Pleasant St SE
    Minneapolis, MN 55455

    • Nuclear Magnetic Resonance Laboratory
    • 194 & 196 Kolthoff Hall, 225 Pleasant St SE
    • Letitia Yao, Ph.D., Director
    • (612) 625-8374