Analysis of kerosene - GCMS

Importance of the topic

The precise characterization of kerosene composition is vital for ensuring fuel quality, meeting regulatory requirements, and optimizing performance in aviation and industrial applications.

Objectives and study overview

This investigation utilizes gas chromatography–mass spectrometry (GCMS) to provide a qualitative profile of kerosene hydrocarbons. Key aims include:

• Assessing separation efficiency of paraffinic and aromatic species
• Comparing non-polar and polar capillary column selectivity
• Addressing challenges in isomer discrimination

Methodology and instrumentation

The analytical method integrates a Shimadzu GCMS-QP1000EX system, leveraging two distinct capillary columns to achieve complementary chromatographic separations.

Instrumentation used

• Shimadzu GCMS-QP1000EX
• Non-polar column: CBJ1, 0.25 mm × 30 m, df 0.25 µm
• Polar column: CBP20, 0.25 mm × 30 m, df 0.25 µm
• Carrier gas: Helium at 50 kPa
• Injector temperature: 300 °C; Interface temperature: 200 °C; Split ratio: 1 : 50
• Temperature programs:
   • Non-polar: 40 °C (2 min) → 220 °C at 5 °C/min
   • Polar: 80 °C (2 min) → 150 °C at 5 °C/min → 200 °C at 15 °C/min

Key results and discussion

• Non-polar TIC detected aromatics up to toluene, indicating minor gasoline contamination.
• Polar TIC showed absence of C8-paraffins and revealed paraffin distribution from C9 to C16, with C10 and C11 predominating.
• Mass chromatograms demonstrated that C3-alkylbenzene eluted between specific paraffins, with retention shifts between kerosene samples A and B.
• Eight C3-alkylbenzene isomers yield highly similar spectra, complicating direct mass-based identification.
• A high-resolution capillary column achieved near-baseline separation of all isomers except the m,p-ethylmethylbenzene pair, facilitating unambiguous identification.

Benefits and practical applications

• Improved resolution of hydrocarbon classes supports routine QA/QC of kerosene fuel batches.
• Enhanced isomer discrimination aids forensic fingerprinting and contamination tracking.
• Robust method enables compliance with regulatory specifications and process control in refining operations.

Future trends and potential applications

Emerging technologies and methodologies will further refine hydrocarbon analysis:

• Multidimensional GC (GC×GC) for comprehensive fingerprinting of trace components.
• Advanced chemometric tools to automate isomer identification and quantitation.
• Miniaturized or portable GCMS platforms for field-based screening.

Conclusion

The combined use of non-polar and polar capillary columns in GCMS provides a powerful approach for detailed kerosene profiling and reliable isomer separation, enhancing analytical accuracy in fuel quality assessment.

References

No external references were cited in the original document