Analysis of Gasoline Blends and Finished Gasolines using Reformulyzer® M4 according to ASTM D6839 & EN ISO 22854 - OPIONA Mode

Significance of the topic

Accurate group‐type analysis of gasoline blends and finished fuels is crucial for quality control, regulatory compliance and optimal refinery operations. Rapid and reliable classification of hydrocarbon classes and oxygenates ensures that automotive fuels meet performance specifications and environmental regulations while supporting blending efficiency.

Objectives and overview

This application note demonstrates the quantitative determination of hydrocarbon types (paraffins, naphthenes, olefins, aromatics) and oxygenates in gasoline blends using the AC Reformulyzer M4 in OPIONA mode. The method is fully compliant with ASTM D6839 and EN ISO 22854. Certified reference materials are analyzed to illustrate precision, speed and standard conformity.

Methodology and instrumentation

The OPIONA mode on the Reformulyzer M4 combines capillary and micropacked columns with a series of traps and valves to achieve full iso/normal separation within a 60-minute cycle. The separation scheme includes:

• A polar column separating paraffins and naphthenes from aromatics
• A pre-column trap retaining heavy aromatics and alcohols
• An ether/alcohol trap directing oxygenates to a boiling point column
• Olefin and 5A traps isolating isomeric and normal olefins/paraffins
• A 13X carbon molecular sieve column for detailed saturate carbon distribution
• A flame ionization detector for quantitation

Used instrumentation

• AC Analytical Controls Reformulyzer M4
• Capillary and micropacked chromatography columns
• Ether/Alcohol, Olefin, 5A and carbon molecular sieve traps
• Boiling point separation column
• Flame Ionization Detector (FID)
• High-purity nitrogen and hydrogen carrier/support gases

Main results and discussion

Representative analyses of Gravimetric Blend 512 and Gasoline N CRMs exhibit clear baseline separations for all target groups. Quantitative profiles for Gasoline N show:

• Weight percentage: saturates ~33%, aromatics ~40%, olefins ~8.8%, oxygenates ~5.4%
• Volume percentage: saturates ~37%, aromatics ~34%, olefins ~9.7%, oxygenates ~6.0%
• Complete iso/normal paraffin and olefin resolution within tolerance ranges

Precision and reproducibility meet the requirements of both EN ISO 22854 and ASTM D6839, confirming the method’s robustness for routine fuel analysis.

Benefits and practical applications

• Rapid full group‐type analysis in 60 minutes
• Complete iso/normal separation for paraffins and olefins
• Compliance with key international standards for gasoline testing
• Wide analytical scope covering C4–C11 hydrocarbons and C1–C6 oxygenates
• Enhanced throughput for refinery QC, blending control and fuel certification

Future trends and potential uses

• Integration with automated sampling systems and LIMS for high-throughput labs
• Extension to emerging biofuel oxygenates and advanced renewable blends
• Coupling with multidimensional GC techniques for increased resolution
• Real-time monitoring of refinery streams and blending operations

Conclusion

The AC Reformulyzer M4 in OPIONA mode delivers a fast, precise and standards-compliant solution for comprehensive group-type analysis of gasoline blends and finished fuels. Its robust iso/normal separation capability and complete coverage of hydrocarbon and oxygenate classes make it an ideal tool for fuel quality assurance and refinery process optimization.

References

• ASTM D6839
• EN ISO 22854
• ASTM D5443
• IP 566
• SH/T 0741
• GB/T 28768-2012