标题: 洗核磁管的新方法-利用干燥器 [打印本页] 作者: victhr 时间: 2016-3-23 21:39 标题: 洗核磁管的新方法-利用干燥器 The operating instructions are presented in Scheme 1.
First, NMR tubes to be washed are emptied and put upside
down inside a beaker (step A). Cleaning solvent or solution
(acetone, methanol, ethanol, water, nitric acid, aqueous NaOH
solution, etc.) is next added to the beaker (about 4 mL for each
tube). The beaker is put inside the vacuum desiccator (step B).
A vacuum is subsequently applied to the system to remove air
inside the tubes. The desiccator is next vented with air, and
solvent will raise and clean inside the tubes. The vacuum/air
vent cycle is repeated 3−4 times to remove all the air inside the
tubes. The whole system can be left for one night for better
results. Sonication of the beaker can also be performed if
necessary as an aid to cleaning (step C). New solvent is
changed, and the cleaning is finished with clean acetone (step
D). This acetone can be used for the next time of cleaning. The
number of NMR tubes that can be cleaned at once depends
only on the size of the beaker and the desiccator. Caution: The
desiccator should be opened in fume hoods. It is also
recommended that the usual precautions (goggles, gloves,
etc.) are taken. The NMR tubes can also be placed directly in
the desiccator.