Accurate Analysis of Glycerol and Glycerides in Biodiesel Oil Using EN 14105 (2011) and Robust Metal MXT Columns

Significance of the Topic

Fatty acid methyl ester (FAME) biodiesel production generates glycerol and glycerides as byproducts whose removal is critical for fuel stability and engine performance. Precise quantification of free glycerol, mono-, di-, and triglycerides ensures regulatory compliance and quality control.

Objectives and Overview of the Study

This work assesses the European standard EN 14105 (2011) methodology for measuring residual glycerol and glycerides in biodiesel, emphasizing the performance of rugged metal MXT-Biodiesel TG columns to improve analytical robustness and durability.

Methodology and Instrumentation

Samples of B100 soy biodiesel were derivatized with MSTFA to reduce polarity and peak tailing. Gas chromatography was performed on a metal MXT-Biodiesel TG column (15 m×0.32 mm ID, 0.10 µm, with a 2 m×0.53 mm ID retention gap) using hydrogen carrier and an Agilent 7890A GC with FID detection. The oven program ranged from 50 °C to 370 °C. Internal standards ((S)-(−)-1,2,4-butanetriol and specific glyceride analogues) enabled quantification via calibration curves and response factors, following EN 14105 protocols.

Key Results and Discussion

Chromatograms exhibited sharp, well-resolved peaks for glycerol and a range of glycerides with minimal overlap. Linearity for glycerol quantification was excellent (R²=1.0000). Relative response factors for glyceryl dinonadecanoate versus trinonadecanoate remained below the method threshold (RRF<1.8), and injection precision was high (%RSD=0.7%, n=7). The metal column maintained stability at high temperatures, showing no degradation or loss of performance.

Benefits and Practical Applications

• Enhanced column lifetime and robustness under harsh conditions.
• Accurate measurement of free glycerol and residual glycerides for quality control.
• Reduced maintenance and downtime compared to fused silica columns.

Future Trends and Potential Applications

The use of high-temperature metal capillaries may expand to other challenging analytes in biofuels and petrochemicals. Advances in derivatization and detection techniques could further improve sensitivity and throughput in routine analyses.

Conclusion

The combination of EN 14105 standardized procedures with metal MXT-Biodiesel TG columns delivers reliable, precise analysis of glycerol and glycerides in biodiesel. This approach supports stringent quality assurance and operational efficiency in biodiesel production.

References

• Kotrba R Bound by Determination Biodiesel Magazine October 13, 2006
• Kotrba R Solving a Great Biodiesel Mystery Biodiesel Magazine September 10, 2012
• EN 14105 Fat and oil derivatives Fatty acid methyl esters FAME Determination of free and total glycerol and mono-, di-, triglyceride contents 2011