Moving tube NMR
From NMR Wiki
Moving Tube NMR [1, 2] is a technique that uses a long NMR tube (approximately 5 feet) that is moved incrementally between scans. The purpose of this action is to remove the relaxing sample portion from the coil and replace it with a pre-equilibrated sample portion, thus skipping the relaxation delay. This technique facilitates experiments requiring a long relaxation delay which may otherwise be too time consuming.
A more detailed description and demonstration of the moving tube technique is given in the publication [1]. For a guided tour of a Moving Tube NMR system, including the automated tube-moving apparatus, see the youtube video [2].
 The first moving tube experiments (as described in the publication) were performed by moving the tube manually. The following picture shows graduate student Kevin J. Donovan beneath the 500 MHz magnet during a moving tube experiment. |
 A triple resonance (carbon-13, hydrogen-1, phosphorous-31) probe was used for the moving tube experiments. To prepare this probe for moving tube experiments, the dewar was removed such that the probe was hollow down the center, as seen in the following pictures. |
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 A two-piece 'tube sleeve' was machined from delrin and placed in the bottom plate of the probe. The sleeve provided enough friction to hold the tube in place, while still allowing it to be moved freely under a light force. |
