Inserting NMR Sample: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
== '''Sample Loading''' == | == '''Sample Loading''' == | ||
=== '''Using the sample gauge''' === | === '''Using the sample gauge''' === | ||
The optimal volume for NMR samples is 500-600 uL for 5 mm regular NMR tubes and ~300 uL for Shigemi tubes. Before the tube is put into the magnet, the optimal position of the tube in the sample holder should be measured in the gauge as shown in the figure below. For best results the sample should be centered relative to the dashed rectangular area of the gauge. | The optimal volume for NMR samples is 500-600 uL for 5 mm regular NMR tubes and ~300 uL for Shigemi tubes. Before the tube is put into the magnet, the optimal position of the tube in the sample holder should be measured in the gauge as shown in the figure below. For best results the sample should be centered relative to the dashed rectangular area of the gauge. | ||
'''IMPORTANT!''' The bottom of the sample should never be lower than the bottom of the gauge! Failure to observe this may lead to sample breakage and damage to the probe! | '''IMPORTANT!''' The bottom of the sample should never be lower than the bottom of the gauge! Failure to observe this may lead to sample breakage and damage to the probe! | ||
Also important is use good sample holders whose o-rings are not worn out. If your sample slides too easily when inside a holder try another one. | Also important is use good sample holders whose o-rings are not worn out. If your sample slides too easily when inside a holder try another one. | ||
'''Figure1. Positions of NMR tube in the gauge'''. Left, regular tube; right, shigemi tube. | '''Figure1. Positions of NMR tube in the gauge'''. Left, regular tube; right, shigemi tube. <br> | ||
[[Image:gauge reg.jpg]][[Image:gauge sch.jpg]] | |||
=== '''Insert and Eject''' === | === '''Insert and Eject''' === | ||
Revision as of 17:14, 20 October 2009
Sample Loading
Using the sample gauge
The optimal volume for NMR samples is 500-600 uL for 5 mm regular NMR tubes and ~300 uL for Shigemi tubes. Before the tube is put into the magnet, the optimal position of the tube in the sample holder should be measured in the gauge as shown in the figure below. For best results the sample should be centered relative to the dashed rectangular area of the gauge.
IMPORTANT! The bottom of the sample should never be lower than the bottom of the gauge! Failure to observe this may lead to sample breakage and damage to the probe!
Also important is use good sample holders whose o-rings are not worn out. If your sample slides too easily when inside a holder try another one.
Figure1. Positions of NMR tube in the gauge. Left, regular tube; right, shigemi tube.
Insert and Eject
In VNMR:
- Click on the Acqi button or type acqi
- Use the Insert and Eject buttons in the Acqi window
In VNMRJ:
- Click on the Setup tab
- Uset the Insert sample and Eject sample buttons in the middle of the screen
You can also type insert or i and eject or e at the VNMR or VNMRJ prompt.
Procedure
- Eject the current sample first. Even if there is no sample in the magnet you need to use eject to create the airflow.
- Remove the ejected sample.
- Verify that you have the airflow to support your sample. Carefully insert the sample in the bore.
- Select insert to lower your sample
Figure2. Acquisition window.
Do not leave the spectrometer with an open bore for long periods of time. If you have to remove a sample and have nothing else to measure, either insert a standard NMR sample or cover the bore with a dedicated plug.
-- Main.GaohuaLiu - 24 Jan 2007