Phase retention control in preparative centrifugal partition chromatography

Area of Science:

• Analytical Chemistry
• Chromatography
• Separation Science

Background:

• Centrifugal Partition Chromatography (CPC) relies on liquid-liquid chromatography principles, using immiscible liquids as mobile and stationary phases.
• Stationary phase loss, or bleeding, from the rotor diminishes separation performance over time.
• Accurate measurement of stationary phase retention is crucial for optimizing CPC applications.

Purpose of the Study:

• To develop an online tool for rapid and straightforward measurement of stationary phase retention in CPC.
• To enable closed-loop control of stationary phase levels through redosing to maintain consistent separation performance.
• To demonstrate the applicability and benefits of the developed system across various CPC configurations and challenging separations.

Main Methods:

• An online measurement tool utilizing a coalescence chamber (CC) and image analysis was developed.
• The CC was connected downstream of the CPC, allowing operation with non-transparent rotors.
• The system facilitated online retention measurement for closed-loop control via stationary phase redosing.

Main Results:

• The developed tool successfully measured retention online, enabling closed-loop control and maintaining separation performance for ~8 hours.
• Stationary phase redosing reduced specific solvent consumption by approximately 53%.
• The method proved effective in both ascending and descending modes, across different rotor volumes, and for systems with significant bleeding.

Conclusions:

• The online retention measurement tool and closed-loop control strategy significantly enhance CPC operational stability and efficiency.
• This approach overcomes limitations of previous methods by allowing the use of non-transparent rotors.
• The system offers substantial solvent savings and maintains separation quality, particularly in demanding applications with severe bleeding.