Utilizing a Novel Splitter to Eliminate Quantitation Bias for Simultaneous GCxGC-TOFMS/FID Characterization of Traditional and Emerging Fuels

Importance of the Topic

Modern analytical chemistry requires accurate characterization of complex fuel mixtures, including both conventional petroleum streams and novel sustainable or recycled feedstocks. Ensuring reliable quantitation and detailed speciation is critical for assessing fuel performance, regulatory compliance, and process optimization. Dual detection combining comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry and flame ionization addresses quantitation bias and enhances analyte identification in a single analysis.

Objectives and Study Overview

This work evaluates a novel flow splitter paired with a reverse-fill-flush modulator in a GCxGC-TOFMS/FID setup. The goal is to preserve flame ionization quantitation fidelity while providing detailed compound classification and mass spectral identification of traditional aviation turbine fuels, synthetic paraffinic kerosenes, hydrotreated esters and fatty acids kerosenes, and waste plastic pyrolysis oils. Group-type analysis templates map hydrocarbon families across the two-dimensional chromatographic space.

Used Instrumentation

• GCxGC system with reverse-fill-flush modulator
• Shift flow splitter for stable MS/FID split ratio
• Pegasus BT time-of-flight mass spectrometer
• Flame ionization detector
• ChromaTOF software for acquisition and processing

Methodology

Samples were analyzed using a dual-column GCxGC configuration. The reverse-fill-flush modulator ensures efficient transfer between columns, while the Shift splitter maintains a constant flow ratio to each detector throughout the temperature program. Group-type classification assigns regions of the contour plot to paraffins, cycloparaffins, monocyclic and polycyclic aromatics. Automated data processing includes peak detection on both detectors, MS deconvolution, library matching, and alignment of MS and FID signals to yield qualitative identifications and quantitative class distributions.

Main Results and Discussion

• Quantitation accuracy with the splitter closely matched FID-only results across the full temperature range, demonstrating minimal bias.
• Contour plots displayed well-defined elution bands for each hydrocarbon class and clear carbon-number distributions in all fuel types.
• Simultaneous MS detection enabled confident identification of heteroatom-containing species with high library similarity scores.
• Waste plastic pyrolysis oils exhibited distinct PAH profiles at different processing stages, illustrating the method’s utility for tracking contaminant evolution.

Benefits and Practical Applications

The combined GCxGC-TOFMS/FID approach with the novel splitter allows robust bulk quantitation and comprehensive speciation in a single run. It is ideally suited for quality control of aviation fuels, characterization of emerging bio and recycled fuels, and monitoring of production processes to detect and quantify trace contaminants.

Future Trends and Potential Applications

Broader adoption of dual detection platforms may extend to on-line monitoring and real-time process control. Advances in data analytics and machine learning are expected to enhance automated classification, predictive modeling of fuel properties, and rapid assessment of novel feedstocks. Integration with additional detectors or hyphenated techniques could further expand analytical reach for complex matrices.

Conclusion

The LECO Paradigm reverse-fill-flush modulator combined with the Shift flow splitter delivers accurate bulk quantitation and detailed speciation of traditional and emerging fuel samples by integrating GCxGC with TOFMS and FID. This configuration overcomes quantitation bias and meets growing demands for advanced fuel analysis in research and industrial laboratories.