Reformulated (RF) Gasoline

Significance of the topic

High-resolution separation of aliphatic and aromatic hydrocarbons is crucial in petrochemical analysis to ensure product quality, compliance with environmental regulations, and efficient process control.

Objectives and overview

This application note describes a gas chromatographic method for resolving a complex mixture of gasoline-related compounds, including a broad aliphatic fraction and nineteen aromatic species from benzene through methylnaphthalenes, using a reformulated Carbowax bonded capillary column.

Methodology

Samples are introduced by split/splitless injection at 220 °C. The oven temperature program begins at 40 °C with a 2-minute hold, then ramps at 5 °C/min to a final temperature of 240 °C, optimizing separation across a wide boiling point range.

Instrumentation used

• Capillary column: 30 m × 0.25 mm I.D. × 1.0 µm film, reformulated Carbowax bonded phase (007-CW-30-1.0F)
• Injector temperature: 220 °C
• Detector: Mass spectrometer (MSD)
• Carrier gas: Helium at a linear velocity of 28 cm/s

Main results and discussion

The method achieved baseline separation of nineteen target analytes. Retention times increased in line with molecular weight and alkyl substitution patterns, with clear resolution even among structural isomers such as dimethyl- and trimethylbenzenes. Peak shapes were sharp and symmetric, supporting reliable quantitation.

Benefits and practical applications

This GC procedure offers robust, reproducible performance for routine quality control in refineries and petrochemical laboratories. It supports regulatory monitoring of BTEX compounds in gasoline streams and assists environmental laboratories in accurately quantifying aromatic pollutants.

Future trends and potential applications

Advancements may include faster temperature programming for high-throughput analysis, alternative stationary phases for enhanced selectivity, and coupling with two-dimensional GC or tandem mass spectrometry to profile even more complex hydrocarbon mixtures.

Conclusion

The described gas chromatographic method on a reformulated Carbowax capillary column provides an efficient, high-resolution solution for petrochemical hydrocarbon analysis, balancing simplicity, reproducibility, and broad applicability across industrial and environmental settings.