Determining the Ester and Linoleic Acid Methyl Ester Content to Comply with EN14103

Significance of the Topic

Fatty acid methyl ester (FAME) analysis is essential to ensure biodiesel quality and regulatory compliance. Accurate determination of total ester content and linoleic acid methyl ester supports engine performance, reduces emissions, and guarantees feedstock traceability.

Aims and Overview of the Study

This study evaluates the EN14103 method using gas chromatography with flame ionization detection to quantify ester and linoleic acid methyl ester content in pure biodiesel (B100). Samples produced from rapeseed, soybean, chicken and pork oils were investigated to assess method robustness across diverse feedstocks.

Methodology and Instrumentation

The procedure employed an Agilent 6850 gas chromatograph equipped with a split splitless inlet and FID detector. A 30 m HP-INNOWax column (320 um id, 0.25 um film) operated under constant helium flow separated methyl esters from C14 to C24. Calibration used methyl heptadecanoate internal standard in heptane. Key GC parameters included inlet temperature 250C, FID at 300C, and an oven program optimized for isothermal regions at 200C and 230C.

Main Results and Discussion

Baseline separation of all target esters was achieved. Chromatograms demonstrated clear profiles for both vegetable and animal oil biodiesel.
Observed compositions:

• Rapeseed oil high in oleic acid methyl ester (C18:1, ~56% m/m)
• Soybean oil rich in linoleic acid methyl ester (C18:2, ~49% m/m)
• Animal fats exhibited elevated palmitic acid methyl ester (C16:0)

Repeatability tests showed absolute differences well below EN14103 limits and RSD values under 1% for most components.

Benefits and Practical Applications of the Method

The validated method offers high precision and reliability for routine quality control of biodiesel. It supports compliance with European standards and enables analysis of diverse raw materials for both blending and pure B100 applications.

Future Trends and Opportunities

Advancements may include coupling GC with mass spectrometry for enhanced identification, automated sample preparation to increase throughput, and adaptation to emerging feedstocks such as algal and waste-derived oils. Integration with online monitoring systems may further improve process control in biodiesel production.

Conclusion

The EN14103 GC-FID protocol on an Agilent 6850 system demonstrates robust performance for quantifying FAME content in various biodiesel samples, surpassing required precision and supporting wide practical implementation.

References

1. EN14103: Fat and oil derivatives Fatty acid methyl esters Determination of ester and linolenic acid methyl ester contents
2. ASTM D6751-03: Standard specification for biodiesel fuel blend stock B100 for middle distillate fuels