Desiccator

Desiccator

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A typical laboratory desiccator

A desiccator is a sealable enclosure containing desiccants used for preserving moisture-sensitive items. Desiccators are commonly used in laboratories to protect chemicals that are hygroscopic or that react with water from humidity.

Design and Function

Desiccators are typically made of heavy glass or plastic and have a lid that seals tightly to prevent moisture from entering. The bottom section of the desiccator contains a desiccant, such as silica gel, calcium chloride, or phosphorus pentoxide, which absorbs moisture from the air inside the desiccator.

The items to be kept dry are placed on a perforated ceramic plate above the desiccant. The lid is usually greased with petroleum jelly to ensure an airtight seal. Some desiccators have a stopcock that allows the air to be evacuated, creating a vacuum inside the chamber, which enhances the drying process.

Types of Desiccators

There are several types of desiccators, including:

• Standard desiccators: These are the most common type and are used for general purposes.
• Vacuum desiccators: These have a stopcock for vacuum applications, allowing for more efficient moisture removal.
• Gas desiccators: These are used when an inert atmosphere is required, such as with pyrophoric materials.

Applications

Desiccators are used in various applications, including:

• Storing hygroscopic chemicals and reagents.
• Protecting sensitive equipment from moisture damage.
• Drying samples in analytical chemistry.
• Preserving biological specimens and archival materials.

Maintenance

Proper maintenance of a desiccator is crucial for its effectiveness. The desiccant must be regularly checked and replaced or regenerated when it becomes saturated with moisture. The seal of the desiccator should also be inspected to ensure it remains airtight.

Related Pages

• Hygroscopy
• Silica gel
• Vacuum chamber
• Moisture analysis