Desiccator

The contents of desiccators are exposed to atmospheric moisture whenever the desiccators are opened. It also requires some time to achieve a low humidity. Hence they are not appropriate for storing chemicals which react quickly or violently with atmospheric moisture such as the alkali metals. A glovebox or Schlenk-type apparatus may be more suitable for these purposes.

Laboratory use

In laboratory use, the most common desiccators are circular, and made of heavy glass. There is usually a removable platform on which the items to be stored are placed. The desiccant, usually an otherwise-inert solid such as silica gel, fills the space under the platform.

A stopcock may be included to permit the desiccator to be evacuated. Such models are usually known as vacuum desiccators. When a vacuum is to be applied, it is a common practice to criss-cross the vacuum desiccator with tape, or to place it behind a screen to minimize damage or injury caused by an implosion.

To maintain a good seal, vacuum grease is usually applied to the flanges.

See also

• desiccation