Improving Separation and Method Development Efficiency Using the Nexera UC/s UHPLC/SFC Switching System

Significance of the Topic

Modern analytical workflows in pharmaceuticals, food safety and environmental testing increasingly demand rapid, high-resolution separation of complex mixtures including chiral molecules and structural isomers. Combining UHPLC and SFC leverages complementary selectivity, enabling faster method development and improved resolution of challenging analytes.

Objectives and Study Overview

This work presents the design and performance of a hybrid UHPLC/SFC switching platform (Shimadzu Nexera UC/s) that allows sequential UHPLC and SFC analyses on a single instrument. The goal is to accelerate method scouting by automatically alternating mobile phases, backpressure and flow paths, and to compare separation performance for various analyte classes.

Methodology and Used Instrumentation

Key features of the system include:

• A shared autosampler, column oven and detector for both LC and SFC modes
• A CO₂ delivery module with back-pressure regulator for SFC
Three solvent delivery units enabling simultaneous pumping of aqueous, organic and supercritical phases

Method scouting was performed on chiral drugs (omeprazole, warfarin) using six chiral columns (CHIRALPAK series) under 36 condition combinations (18 UHPLC, 18 SFC). Dedicated software automated valve switching, line purging, column washing and gradient execution.

Main Results and Discussion

Comparison of UHPLC and SFC separations revealed:

• SFC achieved 3–5× faster analysis times due to lower mobile-phase viscosity and higher diffusivity, without loss of column efficiency
• SFC reversed elution order for some analytes vs UHPLC, improving resolution of overlapping peaks
• Structural isomers (oleanic vs ursolic acid) poorly separated by HPLC were baseline‐resolved by SFC
• Automated method scouting identified optimal UHPLC conditions for omeprazole and best SFC settings for warfarin with minimal operator intervention
• Continuous switching reproducibility tests demonstrated stable retention and peak shape across repeated mode changes

Benefits and Practical Applications

The integrated UHPLC/SFC switching system:

• Reduces bench footprint and capital cost by sharing modules
• Streamlines method development by enabling parallel screening of two orthogonal separation modes
• Improves detection sensitivity and selectivity for chiral and isomeric compounds
• Minimizes manual reconfiguration and risk of operator error

Future Trends and Possibilities for Application

Ongoing prospects include:

• Integration with high-throughput sample preparation robotics
• Expansion to lipidomics and metabolomics where SFC excels for nonpolar analytes
• Machine learning–driven method optimization using orthogonal data sets
• Miniaturized or multiplexed versions for on-site or clinical diagnostics

Conclusion

The Shimadzu Nexera UC/s UHPLC/SFC switching platform provides a flexible, automated approach to combine the speed and unique selectivity of SFC with the robustness of UHPLC. This dual-mode strategy significantly accelerates method scouting and enhances separation of chiral or isomeric targets, delivering practical benefits in quality control and research laboratories.

References

Terada H., Uchikata T., Matsumoto K., Yamaguchi T., Funada Y. Improving Separation and Method Development Efficiency Using the Nexera UC/s UHPLC/SFC Switching System. Shimadzu Corp., Analytical & Measuring Instruments Division; 2018.