Chiral Separation of Triacyclglycerols Isomers by Supercritical Fluid Chromatography

Significance of the Topic

Triacylglycerols (TAGs) are the main constituents of natural oils and fats, playing critical roles in nutrition, metabolism, and industrial applications. Their structural diversity, including positional and chiral isomers, influences physical properties and biological activities. Accurate separation and characterization of these isomers are essential for quality control in food and pharmaceutical industries, as well as for fundamental research into lipid metabolism.

Objectives and Study Overview

This study aimed to develop and optimize a supercritical fluid chromatography (SFC) method for the chiral and positional separation of six TAG isomers. Using the Nexera UC Chiral Screening System and Daicel CHIRALPAK columns, the research focused on method scouting to identify optimal conditions for rapid, high-resolution analysis.

Methodology

The approach employed systematic variation of three key parameters: oven temperature (20, 25, 30°C), modifier concentration (acetonitrile/methanol ratios of 80/20, 70/30, 60/40), and back pressure (10, 15, 20 MPa). A dedicated software tool, Method Scouting Solution, generated and evaluated 27 analytical runs. Standard mixtures containing six TAG isomers (sn-POO, sn-OOP, sn-OPO, sn-PPO, sn-OPP, sn-POP) were analyzed under each condition.

Used Instrumentation

• Nexera UC Chiral Screening System for SFC separations
• Daicel CHIRALPAK IG-3 column (250 × 4.6 mm, 5 μm) for initial screening
• Daicel CHIRALPAK AD-3 and CHIRALCEL series columns for complementary chiral resolution
• Shimadzu LCMS-8050 with DUIS interface and positive-ion mode for mass detection

Results and Discussion

Method scouting revealed that higher back pressure and moderate modifier concentration improved peak resolution, while oven temperature influenced retention times. Optimal separation of all six isomers was achieved at 30°C, 20 MPa back pressure, and 20% acetonitrile/methanol modifier. Overlapped MS chromatograms confirmed baseline separation and compatibility with UV or ELSD detection.

Benefits and Practical Applications

The optimized SFC method delivers high-speed, efficient separation of TAG positional and chiral isomers, reducing analysis time compared to traditional techniques. This workflow is well suited for method development in food quality analysis, lipidomics research, and pharmaceutical impurity profiling.

Future Trends and Potential Applications

Advancements in automated method scouting and expanded chiral column chemistries will further streamline complex lipid analyses. Integration with high-resolution mass spectrometry and multi-dimensional separations may enable deeper characterization of minor lipid isomers in biological samples and industrial products.

Conclusion

A robust SFC-based method was developed for the chiral and positional separation of TAG isomers using the Nexera UC system and CHIRALPAK columns. Method Scouting Solution proved effective for rapid optimization, establishing a versatile platform for lipid analysis.

References

No additional literature references were provided in the source document.