Moisture can compromise sensitive chemicals, affect sample stability and introduce unwanted variability into laboratory procedures. Consequently, controlling humidity is an important consideration when storing moisture-sensitive materials.
Desiccators provide a practical solution by creating an enclosed environment that helps protect samples from atmospheric moisture. From routine chemical storage to specialized vacuum applications, these devices play an important role in laboratories across various industries.
However, not all desiccators perform the same function. Some provide simple dry storage, while others use vacuum technology to assist with moisture removal. Understanding these differences helps laboratories select the most appropriate equipment for their applications.
What Are Desiccators and How Do They Work?
Desiccators are sealed containers designed to maintain a low-humidity environment around stored materials. They typically use a drying agent, known as a desiccant, to absorb or adsorb moisture from the enclosed air.
Common desiccants include silica gel, molecular sieves and other moisture-absorbing materials. As the desiccant removes water vapour, the relative humidity inside the chamber decreases. Consequently, the environment becomes more suitable for storing moisture-sensitive samples.
Unlike drying ovens, conventional desiccators do not actively heat their contents. Instead, they provide a controlled storage environment that helps minimize moisture exposure.
However, the effectiveness of these devices depends on several factors, including:
- The condition and capacity of the desiccant.
- The quality of the chamber seal.
- The frequency of opening and closing.
- The moisture content of stored samples.
- The surrounding laboratory conditions.
For reliable performance, users should inspect seals regularly and replace or regenerate desiccants when necessary.
Where Are Desiccators Used?
Desiccators support numerous applications across research, pharmaceutical, chemical and industrial laboratories.
Chemical and Reagent Storage
Many laboratory chemicals absorb moisture when exposed to atmospheric humidity. This process, known as hygroscopicity, can affect their mass, concentration or chemical properties. Therefore, desiccators help protect hygroscopic reagents, powders and reference materials during storage.
Analytical Chemistry
Accurate weighing requires careful control of environmental conditions. For example, moisture absorption can alter the measured mass of a hygroscopic sample. Similarly, hot crucibles or weighing vessels may absorb moisture while cooling.
Consequently, laboratories frequently use desiccators to cool suitable materials to room temperature before weighing.
Pharmaceutical Research
Moisture can influence the stability and physical properties of pharmaceutical powders, excipients and certain formulations. Therefore, desiccators provide a useful storage environment during research, formulation development and analytical testing.
However, they do not replace validated stability chambers or controlled-humidity storage systems where precise environmental conditions are required.
Electronics and Materials Research
Moisture-sensitive electronic components, specialized materials and certain adhesives may require protection from atmospheric humidity. As a result, desiccators can help preserve material condition during short-term storage and laboratory handling.
Sample Preparation
Certain laboratory procedures require samples to remain dry before further analysis. In these situations, desiccators help minimise moisture uptake between preparation and testing.Nevertheless, users should select the appropriate desiccant and storage conditions for each material.
Glass vs Polycarbonate Desiccators
Traditional glass desiccators have been widely used in laboratories for decades. However, modern polycarbonate alternatives offer several practical advantages.
Glass provides excellent visibility and broad compatibility with many laboratory materials. Nevertheless, its fragility presents handling and safety concerns, particularly in busy environments.Polycarbonate desiccators offer a lightweight, impact-resistant alternative.
Key advantages include:
- Improved durability: Polycarbonate withstands accidental impacts better than conventional glass, reducing the likelihood of breakage during routine handling.
- Lower weight: Lightweight construction makes moving and repositioning equipment easier.
- Excellent visibility: Transparent models allow users to inspect samples without opening the chamber.
- Cost-effective construction: Polycarbonate models can provide an economical solution for routine laboratory storage.
- Practical maintenance: Smooth surfaces simplify routine cleaning and inspection.
However, polycarbonate does not offer universal chemical resistance. Certain solvents can damage the material or cause stress cracking.
Therefore, users should always verify chemical compatibility before introducing solvents or aggressive cleaning agents.Apex Scientific supplies polycarbonate desiccators manufactured by Jeiotech, offering laboratories in South Africa a durable alternative to traditional glass designs.
Vacuum vs Non-Vacuum Desiccators
| Feature | Non-Vacuum Desiccators | Vacuum Desiccators |
|---|---|---|
| Operating principle | Uses desiccants in an enclosed chamber to maintain a dry environment. | Connects to an external vacuum source to reduce pressure inside the chamber. |
| Typical applications | Routine storage of moisture-sensitive chemicals, protecting prepared samples, cooling suitable laboratory vessels before weighing, and protecting materials from ambient humidity. | Applications requiring reduced-pressure conditions and assisting moisture removal from suitable materials. |
| Construction | Jeiotech models feature transparent polycarbonate construction and adjustable drawers. | Jeiotech models feature robust polycarbonate construction and silicone gaskets to help maintain an airtight seal. |
| Humidity monitoring | Selected models include a reference-type hygrometer for a convenient indication of internal humidity. | Depends on the model and its supplied monitoring features. |
| Vacuum performance | Does not require vacuum operation. | Selected models can achieve pressures as low as 1 Torr and maintain vacuum conditions for more than 72 hours under specified conditions, according to the manufacturer. |
| Main advantage | A simpler and more economical solution when vacuum operation is unnecessary. | Supports laboratory applications requiring reliable reduced-pressure environments. |
| Important considerations | Use a calibrated instrument if accurate humidity measurement is required. | Vacuum alone does not guarantee complete drying. Performance depends on the material, moisture content, vacuum level and operating conditions. Ensure the chamber, pump, tubing and accessories are compatible with the intended vacuum level. |
Clear vs Amber Desiccators: Does UV Protection Matter?
Most desiccators feature transparent bodies that allow users to inspect their contents.
However, certain chemicals, reagents and research materials are sensitive to ultraviolet radiation.
Prolonged light exposure may cause degradation, discolouration or changes in chemical properties. For these applications, UV-blocking desiccators provide additional protection. Jeiotech offers selected models with UV-blocking bodies, commonly identified by the letter U in the model designation. These versions help reduce UV exposure while retaining practical visibility.
Nevertheless, UV-blocking construction does not necessarily provide complete protection against every wavelength of light.Therefore, laboratories should confirm the light sensitivity of their materials before selecting a storage solution.
Choosing Between Cubic, Cylindrical and Round Desiccators
| Feature | Cubic Desiccators | Cylindrical Desiccators | Round Desiccators |
|---|---|---|---|
| Design | Rectangular design for organised, space-efficient storage. | Tall chamber designed to accommodate taller laboratory vessels and equipment. | Compact, rounded design for routine laboratory storage. |
| Available capacities | VDC vacuum series: 11, 23, 35 and 45 litres. | 16 and 25 litres. | 6, 10 and 20 litres. |
| Storage suitability | Multiple samples and containers arranged across several levels. | Taller samples and equipment requiring additional vertical clearance. | Individual containers, crucibles and smaller sample quantities. |
| Shelving | Adjustable shelving; selected models accommodate up to six shelves. | Depends on the model and configuration. | Depends on the model and configuration. |
| Space efficiency | Rectangular shape makes efficient use of bench space; stackable designs are available. | Provides additional vertical clearance for taller items. | Compact design suitable for smaller storage requirements. |
| Vacuum features | Selected models include built-in vacuum gauges and three-way valves for vacuum control. | Selected configurations include vacuum gauges and three-way valves. | Vacuum gauge configurations are available. |
| Construction | Integrated polycarbonate construction. | Transparent polycarbonate construction. | Lightweight construction with silicone vacuum seals. |
| UV protection | UV-blocking options available. | UV-blocking bodies available on selected configurations. | Clear and UV-blocking versions available. |
| Key advantage | Organised, multi-level storage with efficient use of bench space. | Accommodates taller laboratory vessels and equipment. | Compact and versatile for everyday laboratory applications. |
Selection tip: Choose a cubic desiccator for organised, multi-level storage, a cylindrical model for taller samples, or a round model for compact, routine storage. Always check the specific model’s dimensions, capacity and features before purchasing.
Important Accessories to Consider
Selecting the correct desiccator involves more than choosing its shape and capacity.
Several accessories can significantly improve functionality and convenience.
Desiccant Trays
- Desiccant trays provide a dedicated location for silica gel or other suitable drying agents.
- They help separate the desiccant from stored samples and simplify replacement.
- Many Jeiotech models include a dedicated polypropylene desiccant tray.
- However, users should confirm the standard accessories supplied with their selected model.
Perforated Shelves
- Perforated shelves improve storage organization while allowing air movement around samples.
- In addition, adjustable shelving helps accommodate different vessel heights.
- Before purchasing additional shelves, check the maximum quantity and load capacity supported by the model.
Vacuum Gauges
- A vacuum gauge allows users to monitor chamber pressure during vacuum operation.
- For example, Jeiotech cubic vacuum models feature standard gauges, while selected round and cylindrical configurations offer gauge-equipped versions.
- A gauge is particularly useful when users need to confirm that the chamber has reached the required pressure.
Three-Way Vacuum Valves
- Three-way valves provide convenient control over vacuum connections.
- Depending on the configuration, they allow users to evacuate the chamber, release the vacuum or introduce a suitable gas.
- Consequently, these valves offer additional flexibility for specialised laboratory applications.
Vacuum Pumps
- Vacuum desiccators require a suitable vacuum source.
- Therefore, users should consider the pump’s ultimate pressure, pumping speed, chemical compatibility and connection requirements.
- For example, applications involving solvent vapours may require additional protection or specialised pump technology.Apex Scientific can assist laboratories in selecting compatible laboratory equipment, including vacuum solutions suited to their applications.
Beyond Dry Storage: Vacuum Mixing and Bubble Removal
Although most desiccators focus on moisture control, specialised vacuum chambers can support additional laboratory processes.
One example is Jeiotech’s VDC-41D Vacuum Defoaming Stirrer. This innovative system combines mixing and vacuum degassing within a single chamber. During mixing, air bubbles can become trapped in viscous liquids, formulations and specialised materials. These bubbles may affect product appearance, consistency or performance.
The VDC-41D addresses this challenge by combining mechanical stirring with reduced-pressure conditions.
Its key specifications include:
- 45-litre internal chamber capacity.
- Maximum stirring speed of 300 rpm.
- Maximum specified viscosity of 6,000 cP.
- Transparent polycarbonate construction.
- Integrated vacuum gauge.
- Three-way vacuum valve.
Potential applications include cosmetic formulations, pharmaceutical development, adhesives, coatings and electronic materials.
For example, removing trapped air from cosmetic mixtures can improve product consistency and appearance.
Similarly, degassing adhesives and coatings can help reduce unwanted bubbles before subsequent processing.This specialized equipment demonstrates how vacuum chamber technology extends beyond conventional moisture-controlled storage.
What Should You Consider Before Purchasing Desiccators?
Before selecting desiccators, laboratories should evaluate their intended applications and practical requirements.
1. Material: Is polycarbonate suitable for the samples and chemicals involved?
2. Shape: Would a cubic, cylindrical or round configuration best accommodate the samples?
3. Capacity: What internal volume and usable dimensions are required?
4. Vacuum: Does the application require reduced pressure or conventional dry storage?
5. Vacuum Pump: Is a suitable pump already available, or must one be supplied?
6. Vacuum Gauge: Does the application require pressure monitoring?
7. Three-Way Valve: Is vacuum release or gas exchange necessary?
8. Desiccant Trays: Are trays included, and are additional units required?
9. Shelving: How many perforated shelves are necessary, and what is the maximum supported quantity?
10. UV Protection: Would a clear or amber UV-blocking body be more appropriate?Answering these questions helps prevent unnecessary expenditure and ensures the selected equipment meets the laboratory’s requirements.
Desiccator Maintenance: Practical Tips for Reliable Performance
Even high-quality desiccators require routine inspection and maintenance. Fortunately, a few simple practices can help maintain reliable performance.
- Monitor desiccant condition. Replace or regenerate drying agents according to their specifications and moisture capacity.
- Inspect seals regularly. Check silicone gaskets for contamination, damage or deterioration that could compromise airtightness.
- Keep sealing surfaces clean. Dust, particles and residue can prevent proper closure.
- Avoid overloading shelves. Always observe the manufacturer’s maximum shelf load and configuration limits.
- Minimise unnecessary opening. Frequent access introduces humid laboratory air and increases the moisture load.
- Check vacuum connections. Inspect tubing, valves and fittings for leaks before operating vacuum models.
- Verify material compatibility. Use only approved cleaning agents and avoid chemicals that could damage polycarbonate components.
Additionally, users should allow suitable hot materials to cool appropriately before placing them inside polycarbonate chambers.By following these practices, laboratories can improve equipment reliability and maintain consistent storage conditions.
Conclusion
Selecting the right desiccator requires an understanding of the application, storage conditions and available accessories.
As a laboratory equipment supplier in South Africa, Apex Scientific offers Jeiotech desiccators for routine moisture protection and specialised vacuum applications. Our range includes conventional cubic models, cubic vacuum chambers, cylindrical and round configurations, and specialised vacuum mixing equipment.
Whether your laboratory requires simple dry storage or a specialised vacuum solution, choosing the correct configuration can improve workflow efficiency and protect valuable samples. Explore more from our LinkedIn and YouTube channel or contact our team for assistance with selecting the right desiccator for your application.
