Kinetic plot method for the optimal column and instrument design for high speed chiral SFC applications

Area of Science:

• Analytical Chemistry
• Chromatography Science

Background:

• High-throughput Supercritical Fluid Chromatography (SFC) is crucial for rapid screening.
• Optimizing separation speed requires understanding factors affecting efficiency and analysis time.

Purpose of the Study:

• To develop a kinetic plot method for evaluating parameters influencing SFC separation speed.
• To identify the primary limitations for achieving high-speed, high-throughput SFC separations.

Main Methods:

• A kinetic plot method was developed and applied to experimental van Deemter data.
• The study analyzed data from state-of-the-art chiral SFC columns with varying particle sizes and dimensions.
• Parameters investigated included column dimensions, particle size, extra-column dispersion, and flow rate.

Main Results:

• The maximum achievable flow rate is the main impediment to high-speed SFC separations.
• Significantly higher flow rates (15-35 mL/min) are needed for 2 µm particle columns to reach kinetic performance limits for 1000-5000 theoretical plates.
• Current instrument flow rate limitations (4-5 mL/min) increase analysis time substantially compared to ideal conditions.

Conclusions:

• Increasing pump flow rate offers the greatest potential for accelerating high-throughput SFC separations.
• Column packing quality influences the optimal flow rate for kinetic performance.
• While reduced extra-column dispersion and higher pressure drops help, they are less impactful than increasing flow rate.