Turbulent Supercritical Fluid Chromatography in Open-Tubular Columns for High-Throughput Separations.

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Supercritical Fluid Chromatography (SFC) is a powerful separation technique.
• Achieving faster separations often leads to reduced resolution.

Purpose of the Study:

• To develop a method for ultrafast separations and chiral compound screening using turbulent flow in SFC.
• To investigate the impact of turbulent flow on separation efficiency and peak capacity.

Main Methods:

• Utilizing high flow rates of carbon dioxide (up to 4.0 mL/min) in gas chromatography open-tubular columns (OTCs).
• Establishing turbulent flow regimes (Reynolds numbers up to 9000).
• Employing a modified UV detector for on-column measurements to eliminate post-column dispersion.

Main Results:

• Observed a significant reduction in plate height upon transitioning to turbulent flow.
• Achieved a nearly 3-fold increase in peak capacity compared to the laminar flow regime.
• Demonstrated a 9-second separation of four polycyclic aromatic hydrocarbons (PAHs) and evaluated chiral separations on stable OTCs.

Conclusions:

• Turbulent flow in SFC dramatically reduces mass transfer resistance, enhancing separation speed and efficiency.
• This method offers a viable alternative to very high-pressure LC systems for achieving high-speed separations without sacrificing resolution.
• The demonstrated column stability and applicability to chiral screening highlight its potential for rapid analysis.