Simulated Distillation Metal GC Columns

Importance of the Topic

Simulated distillation by gas chromatography is a cornerstone technique for characterizing complex hydrocarbon mixtures across the petroleum industry. It enables precise boiling‐point distribution profiling from light ends to heavy residues, supporting quality control, regulatory compliance, and process optimization in refining and petrochemical operations.

Objectives and Study Overview

This whitepaper introduces the Zebron ZB-1XT SimDist™ metal GC column family featuring proprietary Glass Infusion™ technology. Key aims are to demonstrate:

• Enhanced efficiency and resolution compared with leading competitive columns (Restek MXT-1HT, Varian CP-SimDist UltiMetal).
• Column-to-column consistency through individual QC testing, versus conventional batch testing.
• Long-term stability and high‐temperature robustness for ASTM D6352 and D7169 simulated distillation methods.

Methodology and Instrumentation

The performance evaluation employed standardized test protocols and real sample analyses:

• Columns under test: Zebron ZB-1XT SimDist metal tubing (5 m × 0.53 mm × 0.09–0.15 μm), individually QC-tested and glass‐infused for uniform stationary phase coverage.
• Instrumentation: Capillary GC equipped with FID detector; carrier gases hydrogen or helium at constant flow/pressure; on-column or split injections; oven programs to 430–450 °C.
• Comparative metrics: plate count (efficiency), C50/C52 resolution (ASTM D6352 criterion ≥ 2.0), peak symmetry (0.8–1.2), reproducibility (plates/meter variance), and lifetime studies at 400 °C.

Main Results and Discussion

Performance testing revealed:

• Glass Infusion™ yielded sharply defined peaks and eliminated adsorption artefacts, whereas non‐infused competitive columns exhibited tailing and incomplete coverage.
• Efficiency gains of 45–70 % for C50 plates relative to Restek and Varian columns.
• Outstanding reproducibility: four randomly selected ZB-1XT columns showed plates/meter values within ±2 % of the mean, while batch‐tested competitors varied by up to 30 %.
• Resolution stability: Zebron columns maintained C50/C52 resolution above 2.0 over 90 hours at 400 °C (R2 = 0.84), surpassing variable degradation in alternative columns (R2 values as low as 0.04).
• Representative applications confirmed reliable profiling from C5 up to C120 in diverse matrices–crude oils, vacuum distillates, gasolines, diesels, and POLYWAX standards.

Benefits and Practical Applications

Zebron ZB-1XT SimDist columns deliver:

• Enhanced signal‐to‐noise and peak shape enabling trace and late‐eluting compound detection.
• Improved method robustness for ASTM D2887, D6352, D7169, D3710 analyses.
• Reduced downtime and replacement costs due to extended high‐temperature lifetime.
• Simplified column selection via a clear ASTM method‐to‐column recommendation table.

Future Trends and Opportunities

Looking ahead, simulated distillation will evolve through:

• Integration with multidimensional GC and mass spectrometry for improved compositional insights.
• Development of novel high‐temperature stationary phases and nanoengineered column surfaces.
• Automated in-line QC systems leveraging real-time spectral data and machine learning for drift correction.
• Expansion of micro-GC and portable systems for field‐based simulated distillation in environmental and energy applications.

Conclusion

By combining Glass Infusion™ coating uniformity with individual column QC, Zebron ZB-1XT SimDist columns set a new benchmark in simulated distillation performance. Users benefit from superior efficiency, reproducibility, and high‐temperature stability, ensuring reliable boiling‐point distribution analyses across routine and demanding applications.

References

No external literature references were cited in this application note.