GC for quality control of Biodiesel

Importance of the topic

The growing demand for sustainable fuels has elevated biodiesel quality control to a critical role in ensuring engine performance, regulatory compliance and fuel stability. Adherence to European standards such as DIN EN 14214 is essential for reliable production and widespread acceptance.

Study objectives and overview

This application note describes a gas chromatographic method for routine monitoring of biodiesel transesterification efficiency by quantifying mono-, di-, triglycerides, free glycerol and residual methanol. The procedure is aligned with DIN EN 14105 and EN 14110 to guarantee complete conversion of raw oils into fatty acid methyl esters (FAME).

Methodology and instrumentation

• Injection technique: on-column injection using a specialized glass liner (“simple on-column”) to replace traditional retention gaps.
• Column configuration: fused silica capillary (0.53 mm ID) separation column, capable of operating from 60 °C to 400 °C.
• Instrument: Shimadzu GC-2010 gas chromatograph equipped with deactivated liners and appropriate temperature control for biodiesel analysis.

Main results and discussion

The simple on-column injection liner improved gas-tightness and reduced maintenance compared to retention-gap coupling, resulting in enhanced reproducibility of peak areas and retention times. The system demonstrated faster analysis cycles and better peak resolution, benefiting from small-ID capillaries and robust temperature programming.

Practical applications and benefits

• Accurate daily process control of transesterification ensures consistent fuel quality.
• Simultaneous quantification of glycerides and methanol supports compliance with DIN standards.
• Reduced downtime and operational cost through simplified injection and maintenance.

Future trends and potential applications

Integration of simple on-column injection with high-speed GC and small-diameter columns will further accelerate analysis times, improve sensitivity and support automated, real-time monitoring in biodiesel production. These advances can extend to other biofuels and renewable product assessments.

Conclusion

The combination of a specialized on-column injection liner with a modern GC-2010 system offers a reliable, low-maintenance approach for biodiesel quality control. This method meets stringent standards, delivers improved reproducibility and throughput, and supports the expanding role of biodiesel in the renewable energy mix.