Improving the Analysis of 37 Fatty Acid Methyl Esters

Significance of the topic

Fatty acid methyl ester (FAME) profiling by gas chromatography is essential for assessing lipid composition in food products, determining total and trans fats for nutrition labeling, and ensuring compliance with regulatory standards. Detailed FAME analysis supports quality control in food manufacturing and contributes to research on health impacts of different fatty acids.

Objectives and study overview

This application note evaluates the separation performance of a 37-component FAME standard mixture using three Agilent J&W capillary GC columns: CP-Sil 88 for FAME, DB-FastFAME, and DB-FATWAX Ultra Inert. The goal is to identify column chemistry and dimensions that deliver optimal resolution, cis/trans isomer differentiation, and analysis speed.

Methodology and instrumentation

• GC system: Agilent 7890B with flame ionization detector (FID).
• Autosampler: Agilent 7683B automatic liquid sampler, 5 µL syringe.
• Columns and conditions:
  • CP-Sil 88 for FAME (100 m × 0.25 mm, 0.20 µm), helium carrier, 70+ min run time for full baseline separation.
  • DB-FastFAME (30 m × 0.25 mm, 0.25 µm) under constant pressure helium, 18 min analysis.
  • High-efficiency DB-FastFAME (20 m × 0.18 mm, 0.20 µm) with hydrogen carrier, complete separation in under 8 min.
  • DB-FATWAX Ultra Inert (30 m × 0.25 mm, 0.25 µm) for enhanced selectivity of saturated and polyunsaturated FAMEs.

Main results and discussion

CP-Sil 88 provided baseline resolution of all 37 FAMEs, including cis/trans pairs, within a 70-minute run. The DB-FastFAME 30 m column resolved every component in 18 minutes, while the high-efficiency 20 m variant achieved full separation in under 8 minutes. The DB-FATWAX UI column delivered unique selectivity, separating key omega-3 (EPA, DHA) and omega-6 (ARA) FAMEs and most cis/trans isomers, except minor coelution of C18:1 cis/trans.

Benefits and practical applications

These column options offer flexible trade-offs between resolution and throughput. CP-Sil 88 suits comprehensive profiling where maximum separation is required. DB-FastFAME columns enable rapid screening in high-throughput environments. DB-FATWAX UI is ideal for detailed cis/trans and polyunsaturated fatty acid analysis in fish oils and nutritional studies.

Future trends and opportunities

Advances in high-efficiency narrow-bore columns, hydrogen carrier gas, and optimized temperature programming promise further reduction in analysis time. Integration with mass spectrometry detectors and automation will enhance sensitivity and compound identification in complex food matrices.

Conclusion

The study demonstrates that selecting the appropriate capillary GC column chemistry and dimensions enables tailored FAME analysis across applications. High-resolution CP-Sil 88, rapid DB-FastFAME, and selective DB-FATWAX UI columns collectively address diverse analytical needs in food testing.

Reference

• AOAC Official Methods of Analysis (2000), method Ce 2–66.
• IUPAC Standard Methods for Analysis of Oils, Fats and Derivatives, IUPAC Method 2.301.
• F. David, P. Sandra, A. K. Vickers. Column selection for the Analysis of Fatty Acid Methyl Esters. Agilent Technologies Application Note 5989-3760EN, 2005.