5-3) Heated Stirring (2)
Degassing Methods
Heated Stirring (2)
This method uses online heating. Since it enables heating the mobile phase to the same temperature as the column or detector cell, if a solvent with fixed composition is delivered, no bubbles will form and the refractometer baseline will be stable. The more the mobile phase temperature is increased, the higher the degassing ability, but it requires preventing boiling bubbles from entering the suction filter and heating or controlling the temperature of the suction tube and pump head.
Procedure
Attach a condenser to a specialized reservoir bottle and place them on a hot stirrer. To improve temperature control, a warm bath should be used.
Advantages
- Superior stability of dissolved air level.
Disadvantages
- Equipment is bulky and requires a mobile phase bottle with a specialized stopper and water lines.
- For solvent mixtures, solvent mixing ratio errors can occur between preparation and delivery stages.
- Requires time for stabilization.
- Operating cost is high.
Applications
- High-sensitivity analysis using refractometers, electric conductivity detection, or electrochemical detectors.
- Suited to high-sensitivity analysis using UV or fluorescence detection when heated to high temperature.