Lab Desiccants and Drying Agents
Hygroscopic substances and drying agents for use in laboratory settings; drying agents are commonly used to keep other substances and samples dry, or to prevent moisture from forming on/in containers. Products include drying tubes, kits, etc.
Desiccants are typically chemicals or compounds that are hydroscopic (readily absorb moisture). Common desiccants include clays, silica gels, and calcium sulfate.
In the lab, desiccants are commonly used in desiccators and desiccator cabinets, with in-line air and gas drying columns, in absorption bulbs, U-tubes, glove boxes, sealed chambers, and wherever a dry environment is required. They are also used during transport, for storage, and maintaining materials and products ─ everything from clothing to electronics.
The moisture may come from a variety of sources:
- Water vapor in the air
- Moisture in packaging materials
- Moisture from permeation or leakage
Some desiccants contain an indicator or additive that produces a color change with moisture absorption. The indicator allows the user to see when the desiccant has absorbed its maximum amount of moisture and needs to be replaced or regenerated.
Some desiccants can be reused many times simply by heating them in an oven to allow moisture to evaporate. For indicating desiccants, one can also easily tell when the desiccant is again ready to use by the change back to the original color.
Desiccants may be available in a range of mesh or particle sizes. The Tyler Equivalent is a common type of mesh sizing and indicates the number of openings per linear inch of mesh. Common desiccant mesh sizes are 4, 8, and 10 to 12. Size 4 is typically used in gas phase applications; they are larger and less likely to break. Size 8 is smaller and can be more tightly packed.
Fisherbrand™ Humidity Sponges™
Humidity Sponges™ turn any container into a desiccator.
Fisher Science Education™ Calcium Chloride, Anhydrous
CAS: 10043-52-4 Molecular Formula: CaCl2 Molecular Weight (g/mol): 110.98 InChI Key: UXVMQQNJUSDDNG-UHFFFAOYSA-L Synonym: Dowflake,Caltac PubChem CID: 5284359 ChEBI: CHEBI:3312 IUPAC Name: calcium dichloride SMILES: [Cl-].[Cl-].[Ca++]
Fisher Science Education™ Silica gel 6-12 Mesh, Non-indicating
CAS: 1343-98-2 Molecular Formula: O2Si Molecular Weight (g/mol): 60.08 MDL Number: MFCD00011232 MFCD00217788 MFCD00148266 MFCD00603035 MFCD02100519 MFCD06202255 MFCD07370733 InChI Key: VYPSYNLAJGMNEJ-UHFFFAOYSA-N Synonym: Amorphous Silica PubChem CID: 14942 ChEBI: CHEBI:26675 IUPAC Name: silanedione SMILES: O=[Si]=O
Fisher Science Education™ Drierite™
CAS: 7778-18-9 Molecular Formula: CaO4S Molecular Weight (g/mol): 136.13 MDL Number: MFCD00010912 InChI Key: OSGAYBCDTDRGGQ-UHFFFAOYSA-L Synonym: Calcium Sulfate PubChem CID: 24497 ChEBI: CHEBI:31346 IUPAC Name: calcium sulfate SMILES: [Ca++].[O-]S([O-])(=O)=O
Cole-Parmer Drierite 23001 Indicating desiccant; twelve 1-lb packs/carton
Use Drierite desiccants -- anhydrous calcium sulfate in desiccators, drying columns or drying tubes. Choose indicating or non-indicating desiccant indicating desiccant starts blue, then turns pink when regeneration or renewal is necessary.
Ace Glass, Inc. 8 MESH INDICATNG DRIERITE 5 LB
8 mesh Drierite. The granules of calcium sulfate are impregnated with CP cobalt chloride. On dehydration, the active desiccant assumes a distinct blue color. In use, the color changes to a rose-red. 5/lb.
