The preparation of NMR samples for the open-access spectrometers has a large role to play in the quality of the returned data.
Samples must be made up in intact 507-pp NMR tubes only with a minimum tube length of 19 cm (AVII400/1 or AVII400/2; shorter tubes are permitted on the AVIIIHD400/3 and AVIIIHD500).
Samples should be made up to a depth of about 40 mm. For 5 mm NMR tubes (all open-access systems) a sample depth of 40 mm requires approximately 0.75 mL solvent (for 10 mm NMR tubes: approx. 3.15 mL solvent is needed).
Do not shake the capped NMR tube to mix the contents, as leaks will be inevitable.
Filter samples through a cotton wool plug in a Pasteur pipette into the NMR tube.
After cleaning NMR tubes with solvent dry in an oven (<60°C) avoiding dust!