Working process of vacuum centrifugal concentrator

Vacuum Centrifugal Concentrator – Core Workflow

The core workflow of a vacuum centrifugal concentrator is:

Sample Preparation → Loading and Balancing → Parameter Setting → Operation → Venting at End → Sample Retrieval and Post-Treatment

It achieves rapid low-temperature concentration and protects the activity of heat-sensitive samples through the synergistic effects of vacuum-induced boiling point reduction + centrifugal film formation + auxiliary heating.

Core Principles

Vacuum Decompression: Evacuation to 1–100 Pa significantly lowers the solvent boiling point (e.g., water boils at approximately 30 °C under 50 °C conditions), enabling low-temperature evaporation.

Centrifugal Film Formation: High-speed rotation (typically 500–3000 rpm) forms a thin film of sample on the tube wall, increasing evaporation area and preventing bumping and cross-contamination.

Auxiliary Heating (Optional): Interlocked with vacuum; heating starts only after the set vacuum level is reached to gently accelerate evaporation. Temperature is generally controlled from room temperature to 60 °C.

Standard Operating Procedure

Sample and Equipment Preparation

Use vacuum- and heat-resistant centrifuge tubes (0.5–50 mL). Fill no more than 2/3 of the tube volume; remove air bubbles and impurities.

Check instrument sealing, vacuum pump oil level, and pre-cool the cold trap to ensure a clean and stable environment.

Loading and Balancing

Place sample tubes symmetrically in rotor adapters with strict balancing (mass difference ≤ 0.1 g on opposite sides). Close and lock the rotor lid and chamber door securely.

Parameter Setting

Vacuum Level: 50–80 Pa for water/buffers; 10–30 Pa for volatile solvents.

Rotational Speed: 500–1500 rpm for fragile samples; 2000–3000 rpm for rapid concentration.

Temperature: ≤30–40 °C for heat-sensitive samples; 40–60 °C for stable samples.

Time: Set according to target volume, or use automatic end-point mode.

Enable the cold trap to improve trapping efficiency and protect the vacuum pump.

Startup and Operation Monitoring

Press Start. The instrument automatically runs in the sequence: evacuation first → simultaneous centrifugation and heating once set vacuum is achieved.

Monitor for bumping or splashing through the observation window during the initial stage. Pause periodically (every 10–15 minutes) to check volume and avoid over-drying.

Shutdown and Venting

Upon completion, the instrument automatically stops heating, vents slowly (break vacuum), then stops centrifugation.

Direct rapid venting is strictly prohibited to prevent sample aspiration and splashing.

Sample Retrieval and Post-Treatment

Remove sample tubes and rinse the tube wall with pre-chilled buffer to recover residual sample.

Clean the instrument chamber and rotor, turn off the power, and complete usage records.

⚠️ Key Precautions

Balancing Priority: Do not start without proper balancing to avoid damage to the rotor and motor.

Vacuum Sequence: Always apply vacuum before heating to prevent thermal denaturation of samples.

End-Point Control: Strictly control time and temperature for heat-sensitive samples to avoid loss due to over-drying.

Safe Operation: Wear protective gloves to avoid cold injury from low temperatures or vacuum exposure risks.