Small molecule NMR sample preparation

  1. If just collect 1D proton and 1D carbon spectra, (say, your small molecule’s MW: ~400 Da), 10 to 20 mg/ml concentration (corresponding to 25 to 50 mM) and 0.5 to 0.6 ml volume is very normal.
  2. Use deuterated solvents, e.g., CDCl3-d, DMSO-d6, etc. to prepare your nmr samples, this is for NMR locking and shimming purpose and avoiding solvent proton peaks.
  3. Use 5-mm outer diameter, 7- or 8-inches length nmr tubes. You can buy from our VWR storeroom or order online from NORELL with item#: S-5-500-7. (our B800-Luke NMR machine needs 3-mm tubes with item# : S-3-800-7).
  4. Don’t use very “old”, glass-wall scratched, chipped, or top-fractured tubes.
  5. Don’t use lab oven to dry nmr tubes, after cleaning the solid stuff, use plenty of water through a long glass pipette to flush the nmr tube inner bottom for 1 to 2 minutes and lay down on a tray and air dry it.
  6. Fully push the nmr cap onto the tube top, don’t use paper tape to label on your nmr tube.

Hongwei edited on 8/29/2023