Improved Efficiency of Isomer Preparative Operations by Supercritical Fluid Chromatography with Stacked Injection

Importance of the Topic

Preparative supercritical fluid chromatography (SFC) streamlines separation and purification tasks critical in pharmaceuticals and natural products research. By reducing solvent usage and analysis time, SFC addresses efficiency and sustainability demands in industrial and analytical laboratories.

Objectives and Study Overview

This report examines the use of the stacked injection feature on the Nexera UC Prep preparative SFC system to enhance throughput in isomer separations. A comparison with traditional preparative liquid chromatography highlights time savings, followed by practical implementation in chiral separations of omeprazole and warfarin.

Methodology and Instrumentation

• Chromatographic system: Shimadzu Nexera UC Prep preparative SFC
• Autosampler and fraction collector: SIL-40 and FRS-40 with stacked injection capability
• Analytical column: CHIRALPAK IC (250×20 mm, 5 μm)
• Mobile phase: CO₂/methanol (75/25) for SFC, hexane/ethanol (70/30) for LC comparison
• Flow rates: 120 mL/min for SFC, 20 mL/min for LC
• Column temperature: 40 °C (SFC) vs ambient (LC)
• Detection: UV at 303 nm (omeprazole) or 200 nm (warfarin) with high-pressure cell
• Back pressure regulator: 10–15 MPa

Key Results and Discussion

• SFC reduced analysis times by up to 75% compared to preparative LC in chiral omeprazole separation.
• Stacked injection enabled successive sample injections without idle time, increasing fraction collection efficiency.
• In warfarin separations, throughput increased threefold: nine injections in a 10.5-minute run versus three with conventional injection.
• Software simulation in LabSolutions optimized injection intervals, wait times, and fractionation scheduling to prevent peak overlap.

Benefits and Practical Applications

• Enhanced sample throughput reduces solvent consumption and operational costs.
• Streamlined workflows accelerate lead compound screening and impurity profiling.
• Scalable approach for preparative purification of isomeric and chiral compounds in pharmaceutical development.

Future Trends and Applications

The integration of automated injection strategies with advanced detection and data analytics promises further gains. Prospective developments include real-time monitoring of fraction purity, adaptive injection scheduling based on online feedback, and application to continuous-flow processing in industrial-scale purification.

Conclusion

Employing stacked injection in preparative SFC significantly boosts operational efficiency for chiral isomer separations. This approach offers substantial time savings and resource optimization, underscoring its value for pharmaceutical and natural product purification workflows.

References

Shimadzu Corporation. Improved Efficiency of Isomer Preparative Operations by Supercritical Fluid Chromatography with Stacked Injection. First Edition, November 2019.