C6 and Lower Boiling Hydrocarbons in Olefin Free Naphthas Nexis GC-2030LBH1 GC-2014LBH1

Importance of the Topic

Accurate analysis of C6 and lower boiling hydrocarbons in olefin‐free naphthas is essential for quality control, product specification compliance, and process optimization in petrochemical and fuel industries. Precise quantification of light hydrocarbons and aromatics such as benzene impacts safety, regulatory adherence, and downstream processing efficiency.

Objectives and Study Overview

This study documents a gas chromatographic method for simultaneous determination of propane, butanes, pentanes, hexanes, benzene, and related isomers in olefin‐free naphtha samples with final boiling points up to 260 °C. It follows the UOP‐551 protocol and demonstrates method performance on two Shimadzu systems (Nexis GC-2030LBH1 and GC-2014LBH1).

Methodology and Instrumentation

The method employs a split/purge liquid (SPL) injector, a single capillary column, and a flame ionization detector (FID). Key steps include:

• Sample introduction via automatic liquid injection.
• Separation on a high‐resolution capillary column.
• FID detection with optimized temperature and flow programming.

Used Instrumentation

• SPL injector for reproducible micro-litre injections.
• Capillary column suitable for light hydrocarbon separation.
• Single‐channel FID for universal hydrocarbon detection.
• Shimadzu Nexis GC-2030LBH1 and GC-2014LBH1 systems.

Results and Discussion

The method achieved baseline separation of fourteen target compounds, including structural isomers of pentane and dimethylbutane. Calibration ranges spanned from 100 ppm wt to up to 50 % wt, depending on the compound. Chromatograms demonstrated excellent peak resolution and repeatability. Detection limits met or exceeded the requirements of UOP‐551, with potential variation depending on sample matrix.

Benefits and Practical Applications

The described approach offers:

• High reproducibility and sensitivity for regulatory and QA/QC laboratories.
• Comprehensive profiling of light hydrocarbon fractions in naphtha streams.
• Rapid throughput with automated injection and streamlined analysis.

Industries such as refining, petrochemical production, and analytical service providers can adopt this method for routine monitoring and process control.

Future Trends and Potential Uses

Advances in column technology and multi‐detector configurations may enable simultaneous quantification of olefins and trace aromatics. Coupling with mass spectrometry could further enhance selectivity and detection of ultra‐trace components. Automation and data analytics integration will support higher throughput and real-time decision making in industrial environments.

Conclusion

The Shimadzu SGC-ADS-0177 method provides a robust, validated protocol for quantifying C6 and lower boiling hydrocarbons in olefin‐free naphthas. Its alignment with UOP‐551 ensures regulatory compliance, while its performance characteristics support routine analytical demands in petrochemical quality control.

References

• UOP (2011). Method 551: Determination of Light Hydrocarbons in Naphtha.
• Shimadzu Corporation (2017). System Gas Chromatograph Application Note SGC-ADS-0177.