Determination of Fatty Acids Methyl Esters (FAMEs) in aviation turbine fuel by GCMS Scan/SIM mode as per IP585

Importance of the Topic

The reliable measurement of fatty acid methyl esters (FAMEs) in aviation turbine fuels is essential for maintaining engine performance, operational safety and meeting regulatory limits. As the aviation sector explores biodiesel blending to reduce fossil-fuel dependency, sensitive and accurate analytical methods are required to detect trace levels of FAMEs that may affect low-temperature flow, deposit formation and long-term storage stability.

Objectives and Study Overview

This application note presents a gas chromatography–mass spectrometry (GC-MS) method, following IP 585 guidelines, for the determination of six FAMEs in jet fuel (AVTUR). The study evaluates sensitivity, linearity, signal-to-noise performance and recovery in real and spiked fuel samples using Shimadzu GCMS-QP2020 NX with FASST (Fast Automated Scan/SIM Type) functionality.

Methodology and Instrumentation

• Standards: Individual FAMEs and methyl heptadeconate-d33 internal standard (ISTD) prepared in dodecane; calibration stocks at 1 000 ppm.
• Calibration: Low-level (0–10 ppm) and high-level (0–100 ppm) series, each spiked with 10 µL ISTD per 1 mL standard.
• Sample Preparation: 1 mL jet fuel sample plus 10 µL ISTD; spike recovery at 0.5, 25 and 50 ppm.
• Instrument: Shimadzu GCMS-QP2020 NX with AOC-20 autosampler and SH-Stabilwax capillary column (60 m × 0.25 mm, 0.5 µm).
• GC Parameters: Splitless injection (1 µL), constant flow 0.8 mL/min, oven ramp from 150 °C to 252 °C per IP 585.
• MS Parameters: Scan (m/z 32–332, 0.1 s) and SIM (0.3 s) acquisition, interface 260 °C, ion source 230 °C.

Key Results and Discussion

• Linearity: All six FAMEs showed R² > 0.992 over 0–10 ppm and 0–100 ppm when curves were forced through origin.
• Sensitivity: Signal-to-noise ratios at 0.5 ppm exceeded 700 for C18:3 up to >4 000 for C16:0, surpassing IP 585 requirements.
• Recovery: Spike tests in commercial jet fuel yielded recoveries between 86.7 % and 112.4 % across three concentration levels (0.5, 25, 50 ppm).
• Matrix Effects: No FAMEs detected in unspiked fuel batches; spiked samples produced clean SIM chromatograms with well-resolved peaks.

Practical Benefits and Applications

• Meets IP 585 criteria for FAME quantification in jet fuel with high precision and robustness.
• Single-quadrupole GC-MS platform minimizes method complexity while delivering both qualitative (Scan) and quantitative (SIM) data.
• High sensitivity enables detection well below the regulatory limit of 50 mg/kg FAME.
• Suitable for routine QA/QC, fuel certification and support of biodiesel blend optimization.

Future Trends and Opportunities

Ongoing advancements in GC-MS detectors, high-throughput autosamplers and alternative ionization techniques may further lower detection limits and expand FAME profiling to trace oxidation products. Coupling with automated data processing and online monitoring could enable real-time quality control in fuel production and distribution.

Conclusion

This study confirms that the Shimadzu GCMS-QP2020 NX equipped with FASST capability provides a fast, sensitive and compliant approach for quantifying six key FAMEs in aviation turbine fuel. The method demonstrates excellent linearity, sensitivity and recovery, meeting or exceeding IP 585 performance criteria and offering a reliable tool for regulatory and industrial applications.

Reference

• Mathai J., Damale S., Makhamale R., Raju K. Determination of Fatty Acids Methyl Esters (FAMEs) in aviation turbine fuel by GCMS Scan/SIM mode as per IP 585. Shimadzu Middle East Africa FZE-Dubai. Application Note 07-GC-21007-EN, May 2021.