Sample Preparation:

 - use clean + dry NMR tubes and caps (tubes can be re-used, caps should not!)

 - 0.5 ml deuterated solvent (i.e. CDCl3 ,DMSO-d6, acetone-d6 ,etc.)

 - substrate requirements for routine spectra:
        10 mg for proton NMR
      100 mg for carbon-13 NMR

 - min. filling height of tube: 2 inches (5 cm)

 - sample should be clear, completely dissolved and one single phase.
   (no suspensions, no precipitation, filter solution if necessary)

 - cleaning of tubes:
        1. rinse with solvent you were using
        2. rinse with acetone
        3. dry in (vacuum-)oven at low temperature (NMR tubes may warp at higher temperatures!)

Click here to have a look at some spectra.