Volatile liquid handling

For laboratory professionals, this tendency to evaporate presents a unique set of challenges. The characteristics of these liquids—rapid evaporation and low boiling points—can lead to inaccurate measurements, inconsistent experimental results, and potential hazards from flammable vapors. Therefore, mastering the nuances of handling volatile liquids is not only about precision, but also about ensuring the safety, reliability, and reproducibility of scientific research.

Common volatile liquids used in laboratory workflows:

Solvent

Solvents such as acetone, ethanol, and methanol are often used in laboratories. Their high volatility requires careful handling to prevent rapid evaporation, leading to inaccurate measurements and potential fire hazards.

Reagents

Some reagents used in chemical reactions are volatile. Their rapid evaporation can affect reaction results, so it is crucial to handle them quickly and accurately.

petroleum fractions

They are distillates obtained from petroleum distillation, including gasoline, naphtha, etc. Due to its flammability and volatility, special precautions must be taken when handling.

aerosol

While aerosols are not liquids in the traditional sense, they contain volatile components that evaporate rapidly when sprayed and require similar handling precautions.

Best way to dispense volatile liquids

Deal with it calmly

Storing volatile liquids at lower temperatures can greatly reduce their evaporation rate. This method is to store these liquids under refrigerated conditions, usually 2 to 8°C. Before use, the liquid is equilibrated to a specific temperature in a controlled environment to avoid condensation. The use of insulated containers during transfer can help maintain this temperature, ensure accuracy of measurements, and extend the shelf life of some reagents.

Use a fume hood

Fume hoods are essential for handling volatile liquids. Fume hoods capture and vent vapors, providing a safe environment that minimizes the concentration of volatile vapors in the laboratory. To maximize safety and efficiency, it is critical to ensure adequate airflow when the fume hood is operating. Users should work at least 6 inches inside the fume hood and always store volatile liquids in closed containers inside the fume hood to reduce the risk of vapor build-up and potential hazards.

airtight container

Using airtight containers is a straightforward way to maintain the integrity of volatile liquids. Screw caps or other sealing devices are ideal containers. For added safety, wrapping the lid with plastic wrap or Teflon tape can further prevent steam leakage. Regular inspection of these containers ensures they are free of defects, and the use of secondary containment trays catches any accidental spills, ensuring the liquid's purity and volume remain consistent.

Quick transfer

Minimizing the time that volatile liquids are exposed to open air is critical to reducing evaporation losses. This requires planning the workflow in advance and using tools with fast transfer capabilities, such as pipettes or dispensers. When pouring, a funnel speeds up the process and reduces the risk of spills. Containers should be closed immediately after each transfer to ensure accurate liquid volumes and minimize vapor release.

Use dedicated tips for handling volatile liquids

Low suction tips

Low-retention tips are designed to minimize liquid adhesion to their surface, which is useful when working with volatile liquids. Their design ensures that almost all of the liquid sucked in is ejected, which is especially important for small volumes of liquid where evaporation losses can be significant.

Filter tips

Filter tips have a barrier or filter integrated into their design. This barrier prevents inhalation of vapors or aerosols, thus protecting the purity of the sample and the pipette itself. By blocking impurities, these tips ensure consistent results and extend the life of your pipetting instruments.

Positive displacement pipette tips

These disposable pipette tips are uniquely designed with an integrated plunger. The piston is in direct contact with the liquid, bypassing the air cushion typical in standard pipettes. For volatile liquids that evaporate easily, these tips provide a reliable solution, ensuring precise and complete dispensing every time.

How to automate volatile liquid handling processes

Automated liquid handling systems are available for volatile liquids as well as for viscous liquids. These systems can adjust pipetting speed, use specialized tips, and employ algorithms to ensure accurate and reproducible results while minimizing evaporation. Automated processes typically include:

• Calibrate the system for specific volatile liquids.
• Program desired volume and sequence.
• Run test samples to ensure accuracy before full processing.

Advantages of automated handling of volatile liquids compared to manual handling

• Consistency: Automated systems ensure uniform performance and reduce variability.
• Efficiency: Automated systems can process multiple samples simultaneously, increasing throughput.
• Safety: Automated systems can work in enclosed or controlled environments, reducing contact with flammable vapors.
• Precision: By minimizing the time the liquid is exposed to air, automated systems reduce evaporation losses, ensuring more precise results.