Concentrator
A concentrator is a type of laboratory and industrial equipment that removes solvents through evaporation/separation to increase the concentration of solutes in a solution. Its core function is to control temperature, pressure, or airflow to volatilize and recover solvents while protecting target components from decomposition or loss. It is widely used in chemistry, biology, pharmaceuticals, food testing, and other fields.
Main Types and Characteristics
Rotary Evaporator (Rotavapor)
Works by rotating the flask to increase the heating area, combined with reduced pressure and water bath heating to rapidly evaporate solvents, which are then condensed and recovered. Suitable for medium-volume organic solvent samples. Advantages: gentle operation, high recovery rate. Disadvantages: low throughput, suitable for small-batch processing.
Vacuum Concentrator (SpeedVac)
Combines vacuum, centrifugation, and low-temperature control. Under centrifugal force, the sample surface spreads out; low pressure lowers the boiling point, and solvents are trapped by a cold trap. Ideal for micro-volume biological samples (DNA/RNA, proteins, enzymes). Advantages: low-temperature protection against inactivation, no cross-contamination. Disadvantages: limited single-batch processing volume.
Nitrogen Evaporator (Blow-down Evaporator)
Uses high-purity nitrogen gas to gently sweep the sample surface, accelerating solvent evaporation, often with water bath temperature control. Suitable for high-throughput samples in 96-well plates or small test tubes (e.g., pesticide residues, blood samples). Advantages: high throughput, simple operation. Disadvantages: not suitable for high-boiling solvents, incurs nitrogen consumption costs.
Vacuum Parallel Concentrator
Features multi-channel independent sealing, processing dozens of samples simultaneously through reduced pressure, water bath heating, and oscillation. Designed for batch samples in environmental and food testing. Advantages: prevents cross-contamination, extremely high efficiency; suitable for medium-volume batch concentration.
Membrane Concentration System (Ultrafiltration/Nanofiltration)
Under pressure, small-molecule solvents pass through the membrane while large molecules are retained. Used for desalination and concentration of biological macromolecules with 全程 low-temperature and no thermal damage.
Freeze Drying Concentration (Lyophilization)
After low-temperature freezing, solvents sublime under high vacuum. Suitable for extremely heat-sensitive and oxidizable active samples. Disadvantage: time-consuming process.
Core Operating Parameters and Selection Criteria
- Temperature control range and precision: For heat-sensitive samples, choose centrifugal concentration or freeze drying capable of low temperatures (below 0°C).
- Vacuum level: High vacuum (<10 mbar) is required for processing high-boiling solvents.
- Throughput and vessel compatibility: Nitrogen evaporation or parallel concentration for high throughput; vacuum centrifugation for micro-volume samples.
- Safety: Organic solvent processing requires condensation recovery and explosion-proof design to prevent VOC leakage and fire hazards.
Typical Application Scenarios
- Pharmaceuticals: Concentration of drug intermediates, purification of natural product extracts.
- Food: Pretreatment for pesticide residue testing, additive analysis.
- Biology: Concentration of nucleic acid/protein samples, desalination of enzyme preparations.
- Environmental Protection: Concentration of extracts from pollutants in water/soil.
Operation and Maintenance
- Anti-bumping: Control heating rate, add boiling chips, and avoid sudden pressure changes.
- Solvent recovery: Ensure the condensation system functions properly to prevent organic solvent emissions.
- Regular cleaning: Prevent residual corrosion of pipelines; maintain vacuum systems by regularly replacing oil or servicing diaphragm pumps.
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