Analysis of SAF Using Comprehensive Two- Dimensional Gas Chromatography (GC× GC)

Significance of the Topic

Comprehensive compositional analysis of Sustainable Aviation Fuel (SAF) is essential for ensuring performance, meeting regulatory standards and advancing carbon neutrality goals. Two-dimensional gas chromatography coupled with high-speed mass spectrometry provides enhanced resolution and detection of complex hydrocarbon mixtures, supporting robust quality control and additive quantification.

Objectives and Overview

This study evaluates three SAF-related samples (two finished fuels and one intermediate) using GC×GC/GCMS-QP2050. The aims are to generate two-dimensional chromatographic images, compare hydrocarbon distributions across samples, optimize separation of paraffins, naphthenes and aromatics, and demonstrate simultaneous quantitative analysis of the antioxidant BHT.

Methodology and Instrumentation

GC×GC configurations employed various column pairings: a non-polar first column with a medium-polarity second column, and a medium-polarity first column with a non-polar second column. Thermal modulation was achieved with a ZX1 liquid-nitrogen modulator to produce narrow peaks. The GCMS-QP2050’s Fast Automated Scan/SIM Type (FASST) delivered ultrafast scan rates (30 000 u/sec), allowing concurrent full-scan acquisition and SIM monitoring. Key operational parameters included split injection, tailored oven temperature programs, modulation periods of 6–11 s, and helium as the carrier gas.

Main Results and Discussion

Two-dimensional chromatograms clearly differentiated sample compositions. The low-polarity→medium-polarity sequence separated sample A (rich in paraffins and naphthenes) from sample B (higher aromatic content), while the intermediate sample C contained only low-boiling paraffins and naphthenes. The medium-polarity→non-polar configuration improved resolution of paraffin isomers and distinguished mono-, di- and triaromatic species in both SAF and diesel samples. FASST-enabled SIM analysis achieved a 95% recovery rate for BHT at 20 mg/L against an external calibration curve.

Practical Benefits

• Intuitive two-dimensional images support rapid quality assessment of fuel batches.
• Flexible column combinations allow customization for diverse hydrocarbon profiles.
• Simultaneous compositional and trace-additive quantitation aligns with ASTM D2425 requirements.

Future Trends and Opportunities

Further enhancements may involve increased modulation speeds for higher peak capacity, integration with on-line monitoring platforms in production environments, and expansion of spectral libraries for automated compound identification. Coupling GC×GC with advanced detection technologies could improve sensitivity for ultra-trace components and broaden applications in fuel analytics.

Conclusion

The GC×GC/GCMS-QP2050 approach delivers a powerful toolset for detailed SAF analysis. Superior separation, clear component visualization and simultaneous additive quantification address both quality control and regulatory needs, offering significant potential for broader adoption in industrial fuel analysis.