Quantitative Analysis of Tocopherols in Vegetable Oils Using Supercritical Fluid Chromatography

Significance of the Topic

Vitamin E, comprising tocopherols, is a vital fat-soluble antioxidant in plant oils that contributes to neurological function, muscle integrity, cardiovascular health and immune performance.
Supercritical fluid chromatography (SFC) with CO₂ provides high diffusivity and low viscosity compared to liquid chromatography, enabling faster separation while reducing organic solvent consumption.

Objectives and Study Overview

This study demonstrates the simultaneous quantification of four tocopherol isoforms (α, β, γ, δ) in various vegetable oils using a Shimadzu Nexera UC SFC system.
Key goals include improving analysis speed, maintaining resolution and minimizing solvent usage relative to normal phase liquid chromatography (NPLC).

Methodology and Instrumentation

• SFC System: Shimadzu Nexera UC with supercritical CO₂ and ethanol modifier.
• Column: Polar diol stationary phase (e.g. Waters Torus Diol, 100 mm × 4.6 mm, 3 µm).
• Mobile Phase: CO₂ (A) with 2–10 % ethanol (B) gradient over 4 min.
• Flow Rate: 3.0 mL/min; Column Temp: 40 °C; Back Pressure: 15 MPa.
• Detection: UV at 290 nm.
• Calibration: Linear ranges established for each tocopherol with r² ≥ 0.9995.
• Sample Prep: Vegetable oils diluted in n-hexane and homogenized by vortex.

Main Results and Discussion

• Analysis Time: SFC separation completed in 4 min versus ~10 min in NPLC.
• Calibration: All tocopherol calibration curves showed excellent linearity (r² ≥ 0.9995).
• Oil Profiles:
  • Sunflower oil was dominated by γ-tocopherol.
  • Olive oil showed high α-tocopherol content.
  • Palm oil contained significant α- and γ-tocopherols.
  • Sesame oil exhibited a balanced distribution of all four isoforms.

Benefits and Practical Applications

• Reduced organic solvent consumption lowers operational cost and environmental impact.
• High throughput due to shorter run times increases laboratory productivity.
• Maintained resolution ensures reliable quantification for quality control and research.

Future Trends and Opportunities

Advancements in supercritical fluid technology, alternative green modifiers and novel stationary phases may further enhance sensitivity, selectivity and sustainability in lipid and vitamin E analysis.

Conclusion

The Shimadzu Nexera UC SFC method enables rapid, reliable and solvent-efficient quantification of tocopherol isoforms in vegetable oils, offering a compelling alternative to traditional NPLC approaches.

References

• No literature references were provided in the original text.