New GC Column Technology for Old Problems in Fatty Acid Analysis

Importance of the Topic

Fatty acid profiling is essential across food, feed and supplement industries for nutritional labelling, quality control and regulatory compliance. Detailed analysis of free fatty acids (FFAs), fatty acid methyl esters (FAMEs) and triglycerides underpins authenticity testing, process monitoring and health research into omega-3 and omega-6 fatty acids.

Objectives and Overview

This work presents next-generation gas chromatography (GC) column technologies designed to overcome challenges in fatty acid analysis. Key aims include improving inertness for polar free acids, enhancing resolution of cis/trans and positional isomers, reducing run times, and extending column lifetime. New stationary phases (DB-FATWAX UI and DB-FastFAME variants) are evaluated alongside Agilent’s Intuvo 9000 GC platform.

Methodology

Samples (oils, fats, beverages) undergo acid/base hydrolysis and transesterification to produce FAMEs. FFAs are separated directly when required. GC separations employ polar and cyano-functional phases to exploit dipole interactions and maximize isomer resolution. Flame ionization detection (FID) is used for quantitation; mass spectrometry (MS) may supplement when structural identification is needed. Critical sample introduction steps utilize inert liners with glass wool to prevent discrimination of low and high boiling analytes.

Instrumentation

• GC Systems: Agilent 7890, 8890 and Intuvo 9000
• Columns: DB-FATWAX UI (30 m×0.25 mm×0.25 µm); DB-FastFAME (20, 30, 60 and 90 m×0.18–0.25 mm id); CP-Sil 88 (100 m) and SP-2560 for comparison
• Triglyceride Phase: CP-TAP CB (25 m×0.25 mm×0.10 µm)
• Acid Analysis: DB-FFAP (30 m×0.25 mm×0.25 µm)
• Carrier Gases: Hydrogen (constant pressure), Helium (constant flow)
• Inlet: Split injection with inert liners; guard chips on Intuvo
• Detector: FID with nitrogen or hydrogen makeup gas

Main Results and Discussion

DB-FATWAX UI demonstrated superior inertness for FFAs, eliminating tailing and extending column life compared to conventional wax phases.
DB-FastFAME columns achieved baseline resolution (RS ≥1.95) of critical cis/trans C18:1 isomers in under 24 minutes on 30 m phases, and in 7 minutes on 20 m Intuvo modules. A 90 m DB-FastFAME phase resolved 63 FAME components in <48 minutes, 30–35% faster than SP-2560. Crude rapeseed oil FAMEs were separated in <14 minutes with a 60 m Intuvo column.

Benefits and Practical Applications

• Enhanced throughput via faster run times and reduced cycle times
• Improved isomer separation supports accurate cis/trans labelling and compliance with AOAC, AOCS and IUPAC methods
• Greater phase inertness minimizes column contamination and maintenance costs
• Modular Intuvo platform simplifies column installation and reduces startup delays

Future Trends and Opportunities

Ongoing innovations include direct-heating GC modules with guard chips, click-and-run column connections and integration of high-resolution phases with automated sample introduction. Future work may focus on coupling these phases with MS for structural elucidation, expanding high-throughput lipidomics, and embedding real-time analytics into manufacturing pipelines.

Conclusion

Advanced GC column technologies such as DB-FATWAX UI and DB-FastFAME deliver significant improvements in inertness, resolution and speed for fatty acid analysis. When combined with modern GC platforms like the Intuvo 9000, these developments enable robust, high-throughput workflows that satisfy stringent regulatory and quality demands.

References

1. Application note 5991-8706EN: Analysis of 37 FAMEs using capillary columns
2. Application note 5991-8744EN: Omega-3/6 FAME analysis in fish oil
3. Application note 5991-9223EN: Volatile organic and fatty acid comparison study
4. Brochure 5991-8763EN: Comprehensive analysis of FAMEs, fatty acids and triglycerides
5. Application note 5991-9482EN: Fast FAME analysis on Intuvo 9000
6. Application note 5994-0116EN: Rapid FAME separation with DB-FastFAME
7. Application note 5994-1862EN: High-resolution 63-component FAME separation