UIC Chemistry NMR Facility
Sample Preparation Tips

1. Sample Tube.
Only good-quality NMR sample tubes such as Wilmad 507-PP or 528-PP or other vendor's equivalents should be used. The new Avance-400 and -500 MHz machines require the use of a 528-PP tube or better.

If you are preparing samples for use with the sample-changer on the Varian Mercury-Vx-300 you MUST USE a tube of at least 8" length!

2. Sample Volume.
For conventional samples in organic solvents the best results will be obtained using a sample volume of 0.7 - 0.8 mL. Smaller volumes can be used but will require much more shimming.

3. Sample Quality.
When making up the sample, place the sample in a small vial and add the solvent to the vial. Make up a filter using a small piece of Kimwipe inserted into a Pasteur pipette. Put the NMR tube in a holder and insert the filter pipette into the NMR tube. After dissolution, draw the solution up with another pipette (not the one with the filter), and then introduce the solution into the NMR tube through the filter pipette.

4. Sample Solvents.
Solvents should be kept dry and free from impurities. Molecular sieves can be used to dry solvents; these create particulates which must be removed using the filtering method described above.

5. Sample Referencing.
For conventional H-1 and C-13 NMR, our NMR equipment does not need TMS or any other reference materials in the NMR tube. We ask that these not be added to the sample unless you are specifically requested to do so.