NMR FAQs

Is there a submission form to fill out when I drop off my samples?

Yes, we have one form for Univeristy of Guelph users and another for external groups (companies, other universities, etc.).

Are there instructions on how to use the NMR spectrometers?

The New Users' Guide describes how to use the 400 MHz spectrometer and how to process data and prepare plots. Detailed instructions for advanced experiments are posted beside each spectrometer.

How do I view and process my data on my lab or personal computer?

The New Users' Guide also describes how to download your NMR data and how to install a free, academic version of Topspin 4.0 from Bruker. 

What are "best practices" for preparing NMR samples?  

We recommend a sample concentration of 1-2 mg/mL for 1H NMR, and 20-50 mg/mL for 13C NMR. The sample should be completely dissolved in 600 microlitres of a deuterated solvent and mixed throughourly in a glass vial, and then transferred to a clean, dry NMR tube (mixing directly in the NMR tube often leads to poor shims/lineshapes). If necessary, the sample should be filtered to ensure there are no insoluble particles present. Some solvents, like DMSO and D2O get 'wet' unless tightly sealed and the water peak in the spectrum can obscure areas of interest. Using a single ampule for each sample works best. 

What kind of NMR tube should I use?

Only Wilmad or Shigemi brand tubes are allowed in the NMR Centre. Wilmad tubes must be of grade 506-PP or higher. Please contact NMR staff prior to using any other kind of tube (e.g. sealed tubes).

The tube must not be chipped, cracked, or warped in any way or else it could damage or break in the probe (costing thousands of dollars to repair). New tubes can be purchased from Chemistry Stores (in Science Complex) or by contacting NMR staff.

(Aside - don't bake your tubes in a hot oven to dry, or they may warp. If it is necessary to dry them, use a 70 C oven, and lay them flat.)

How should I clean my NMR tube?

Use an NMR tube washer to rinse the tube with at least three volumes of the same (non-deuterated) solvent. Then, rinse one final time with a low boiling point solvent (e.g. acetone). Dry the tubes by laying them flat in a 70 C oven. Avoid higher temperatures which may warp the tubes (warpage of even a few micrometers can cause breakage inside the NMR probe).

For biomolecular aqueous samples, soak the tubes overnight in 5% HNO3, then rinse with multiple volumes of water until the pH of the rinsate is netural. If a film remains in the NMR tube, let the tubes soak in 1 M NaOH for one hour, then repeat the HNO3 and rinsing steps. Do not use stronger NaOH or longer times or else you will etch the tubes. Dry the tubes as described above.

How did you get the 800 into the lab?

A large opening was made in the side of the Science Complex, directly into the nearby AAC staff lounge. Large double-doors were installed in the lounge and the NMR lab, allowing the magnet to be brought in.