Analysis of FAME in partially hydrogenated soybean oil

Significance of the Topic

Profiling fatty acid methyl esters (FAME) in partially hydrogenated soybean oil is essential for nutritional assessment, quality control and regulatory compliance. Accurate separation and quantification of cis- and trans-isomers directly impact public health guidelines and food labeling requirements.

Study Objectives and Overview

The application note aims to demonstrate high-resolution gas chromatographic separation of FAME using Agilent’s CP-Select CB column. Key goals include optimizing selectivity for cis- and trans-fatty acids, evaluating column stability under bake-out conditions, and assessing loadability for complex mixtures.

Methodology and Instrumentation

Agilent employed a capillary GC system with the following conditions:

• Column: Agilent CP-Select CB for FAME, 0.25 mm × 100 m, WCOT
• Oven temperature: 185 °C
• Carrier gas: He at 1.3 bar
• Injector: Split mode (1:100), 250 °C
• Detector: FID at 250 °C
• Sample: 1 µL bean oil methyl esters

These parameters ensure optimal peak shape and reproducible response for trace analytes.

Key Results and Discussion

The CP-Select CB for FAME column achieved:

• Excellent resolution of 21 FAME peaks, including saturated (C16:0, C18:0, C20:0), monounsaturated C18:1 isomers (cis/trans at positions 7–15) and polyunsaturated C18:2 pairs (cis/trans combinations)
• Low bleed at high temperatures (up to 290 °C), enabling fast bake-out and minimal baseline noise
• High loadability—at least three times greater than conventional polar phases, improving separation of closely eluting isomers
• Robust performance under splitless and on-column injection without efficiency loss

The bonded polar phase delivered stable selectivity comparable to CP-Sil 88 while extending operational lifetime and quantitative accuracy for trace components.

Benefits and Practical Applications

Implementing the CP-Select CB column for FAME analysis provides:

• Reliable cis/trans isomer quantification for nutritional labeling and trans fat monitoring
• Enhanced throughput due to rapid oven bake-out and consistent column performance
• Improved QA/QC in food, feed and agricultural laboratories
• Compatibility with sensitive detectors (e.g., MS) for comprehensive profiling of complex matrices

Future Trends and Opportunities

Advances likely to shape FAME analysis include:

• Integration of two-dimensional GC for deeper isomer resolution
• Coupling with high-resolution MS to detect trace-level positional isomers
• Development of greener carrier gases and shorter columns for faster analyses
• Automated data processing and AI-driven peak identification to streamline workflows

Conclusion

Agilent’s CP-Select CB for FAME column offers superior separation, stability and loadability for detailed profiling of partially hydrogenated soybean oil. Its robustness and low bleed profile make it ideal for routine cis/trans fatty acid analysis in regulatory and research settings.

References

Agilent Technologies, Inc. Analysis of FAME in partially hydrogenated soybean oil. Application Note A01775, 2011.