FAMEs Analysis of Oils by GC-FID Coupled with Fully Automated Sample Preparation using a PAL3 Series 2 RTC

Significance of the Topic

The characterization of fatty acid methyl esters (FAMEs) is critical for food quality assessment, regulatory compliance, and accurate nutrition labeling. Detailed lipid profiling supports consumer health decisions and meets global quality control requirements. Fully automated sample preparation enhances laboratory safety, throughput, and consistency while minimizing human error.

Objectives and Overview of the Study

This work evaluates two fully automated derivatization workflows for FAME analysis in edible oils using the PAL3 Series 2 RTC autosampler coupled with an Agilent 8890 GC-FID. The study compares a rapid base-catalyzed protocol (KOH) and a comprehensive acid-base-catalyzed protocol (KOH + BF3), assesses chromatographic performance, and examines reproducibility across different systems.

Methodology and Instrumentation

• Standards and Samples: A 37-component FAME standard (Sigma-Aldrich CRM47885) and three consumer-grade oils.
• Automated Derivatization Workflows:
  
  • Base-Catalyzed (M5795-14000): Methanolic KOH reaction followed by heptane/hexane extraction.
  • Acid-Base-Catalyzed (M5795-14001): Sequential methanolic KOH and BF3 reactions for comprehensive conversion of complex lipid classes.
• Gas Chromatography Conditions:
  
  • Column: Agilent DB-FastFAME, 30 m × 0.25 mm, 0.25 µm.
  • Inlet: 275 °C, split 50:1.
  • Oven Program: 70 °C (0.5 min) → 165 °C at 60 °C/min (0.5 min) → 200 °C at 10 °C/min (0.5 min) → 230 °C at 5 °C/min (2 min).
  • Carrier Gas: Hydrogen at 3.0 mL/min.
  • Detector: FID at 300 °C.

Instrumentation Used

• PAL3 Series 2 RTC autosampler for automated sample handling and derivatization.
• Agilent 8890 GC system equipped with DB-FastFAME column.
• Flame Ionization Detector (FID) for quantitation.

Key Results and Discussion

Both workflows achieved baseline resolution (>1.5) for all 37 FAME components in under 15 minutes. Precision studies on olive, canola-olive blend, and hemp oils demonstrated RSD values below 5% across two separate systems. The base-only method offered faster turnaround, while the acid-base approach improved compatibility with free fatty acids and complex lipid classes.

Benefits and Practical Applications

• Reduced manual solvent handling and exposure risks.
• Increased throughput and consistent sample processing.
• High reproducibility across instruments, supporting inter-lab comparisons.
• Applicability in QC, regulatory testing, and research for reliable lipid profiling.

Future Trends and Opportunities

Future developments may integrate on-line mass spectrometric detection, advanced autosampler configurations, and AI-driven data analysis. These advances will further streamline workflows, expand the range of detectable lipid species, and support high-throughput food and bioanalytical testing environments.

Conclusion

Fully automated sample preparation combined with GC-FID provides a robust platform for FAME analysis in food oils. Both KOH-only and KOH-BF3 derivatization workflows deliver accurate, reproducible results, enhancing lab safety and operational efficiency for routine lipid analysis.

References

1. Godina, L. Analysis of Oil and Fat Containing Foods by Fully Automated Sample Preparation Using a PAL3 Coupled with 7890 GC and a 5977 MSD System According to AOAC 996.01. Agilent Technologies Application Note, 5991-9107EN, 2018.
2. Zou, Y. H. Improving the Analysis of 37 Fatty Acid Methyl Esters. Agilent Technologies Application Note, 5991-8706EN, 2023.