SULFUR IN GASOLINE: LIGHT PETROLEUM LIQUIDS ACCORDING TO ATSM D5623

Significance of the Topic

Reliable quantification of sulfur in gasoline is critical for environmental compliance, equipment protection, and process optimization in the petrochemical industry. Sulfur compounds can accelerate corrosion, poison catalysts, and generate odors, making sensitive detection at low concentrations essential throughout refining operations.

Objectives and Study Overview

This study evaluates the performance of the Agilent Intuvo 9000 gas chromatograph coupled with an 8355 Sulfur Chemiluminescence Detector (SCD) according to ASTM D5623. It aims to demonstrate chromatographic equivalence to conventional GC systems while highlighting advantages such as reduced footprint and simplified maintenance.

Methodology and Instrumentation

The analytical procedure employed split injections (10:1) of standards containing 22 sulfur compounds (0.1–100 ppm) prepared in isooctane. A 30 m Intuvo DB-1 capillary column (0.32 mm × 1 µm) was used under a standard oven program. The SCD was operated at manufacturer-recommended temperatures and flows.

Instrumentation:

• Agilent Intuvo 9000 GC
• Agilent 8355 Sulfur Chemiluminescence Detector
• Intuvo DB-1 column (30 m × 0.32 mm, 1 µm)
• Split injector (10:1 ratio)

Results and Discussion

Linearity and repeatability were assessed across four concentration levels (0.1, 1, 10, 100 ppm). The average relative standard deviation of peak areas ranged from 4.1% at 0.1 ppm to 2.2% at 100 ppm, with an overall R2 of 0.999, confirming excellent precision and linear response.

Chromatograms at 10 ppm displayed sharp, well-resolved peaks for all analytes. At 20 ppb, over half of the compounds produced signal-to-noise ratios above 3, establishing a practical detection limit of approximately 2 ppb under the test conditions.

Benefits and Practical Applications

The Intuvo 9000 GC-SCD system delivers equivalent analytical performance to traditional GC setups while offering:

• Compact footprint (approximately half the size of conventional GC)
• Enhanced flow-path robustness
• Faster column changeover for method development
• Reduced maintenance complexity

This makes it well suited for routine monitoring of sulfur impurities in fuel streams, quality control, and research laboratories.

Future Trends and Opportunities

Advances in detector sensitivity and miniaturized GC platforms point toward further reductions in analysis time and detection limits. Integration with automated sampling and real-time data analytics may facilitate on-line monitoring of sulfur species in refining and petrochemical processes. Future work could explore multiplexed detection and coupling with other selective detectors for comprehensive sulfur speciation.

Conclusion

The Agilent Intuvo 9000 GC equipped with an 8355 SCD meets the stringent requirements of ASTM D5623 for sulfur determination in gasoline. It offers robust chromatographic performance, excellent repeatability, and low detection limits, combined with operational advantages in footprint and maintenance.

Reference

1. Veeneman, R.; Smith, A. Detection of Sulfur Compounds in Gasoline According to ASTM D5623 with Agilent’s Dual Plasma SCD, Agilent Technologies Application Note 5991-6577EN, 2016.
2. Veeneman, R. Detection of Sulfur Compounds in Gasoline According to ASTM D5623 with Agilent’s Intuvo GC and SCD, Agilent Technologies Application Note 5991-7215EN, 2016.