Performance Assessment of Nexis™ SCD-2030 Using Sulfur Compounds Recommended by ASTM D5623

Significance of the Topic

Effective detection and quantification of sulfur compounds in light petroleum products are essential for environmental protection, fuel quality control, and regulatory compliance. Sulfur chemiluminescence detection offers high sensitivity and selectivity in complex hydrocarbon matrices, making it a valuable analytical approach.

Aim and Overview of the Study

This study evaluates the performance of the Shimadzu Nexis SCD-2030 system in accordance with ASTM D5623 guidelines. The objective is to assess its precision, linearity, and long-term stability using a set of nineteen sulfur compound standards representative of gasoline-range samples.

Methodology and Instrumentation

• Gas chromatograph: Nexis GC-2030 with AOC-20i plus autosampler
• Detector: SCD-2030 sulfur chemiluminescence cell with horizontal redox configuration
• Column: SH-Rxi-1MS, 30 m × 0.32 mm I.D., 4 µm film thickness
• Injection: 1 µL split mode, ratio 1:9, injector temperature 275 °C
• Carrier gas: helium, constant flow at 2.8 mL/min
• Oven program: hold 40 °C for 3 min, ramp 10 °C/min to 250 °C, hold 16 min
• Detector settings: interface 200 °C, furnace 850 °C; reagent gases H₂ (100 mL/min), N₂ (10 mL/min), O₂ (12 mL/min), O₃ (25 mL/min)
• Standards: nineteen sulfur compounds split into two mixtures (one in n-hexane, one in toluene) at 10 ppm, each spiked with diphenyl sulfide (1 ppm) as internal standard

Main Results and Discussion

• Chromatographic separation of all 19 target analytes was achieved with clear baseline resolution and no interference from solvent peaks.
• Repeatability across concentrations (0.1, 1, 10, 100 ppm) showed relative standard deviations below 10%, and calibration curves delivered correlation coefficients above 0.9999 for all compounds.
• Long-term performance monitored over 16 days for four representative compounds (spanning boiling points from 98 °C to 273 °C) yielded response factor RSDs below 3% and absolute area RSDs below 4%, demonstrating exceptional stability.

Benefits and Practical Applications

• The high selectivity of the SCD-2030 ensures reliable sulfur detection even in complex fuel samples.
• Broad linear dynamic range and low detection limits support routine fuel quality monitoring and regulatory testing.
• Robust long-term stability reduces the need for frequent recalibration and enhances laboratory productivity.

Future Trends and Applications

• Automation of sample preparation and data processing will streamline sulfur analysis workflows.
• Expanding the method to heavier hydrocarbon fractions and additional sulfur species can broaden its industrial relevance.
• Application of SCD technology in environmental and emissions testing will become more prevalent as regulations tighten.

Conclusion

The Shimadzu Nexis SCD-2030 system meets and exceeds ASTM D5623 requirements, offering precise, linear, and stable analysis of sulfur compounds in light petroleum products. Its strong performance characteristics make it an ideal choice for laboratories engaged in fuel quality control and regulatory compliance.

Reference

• ASTM D5623: Standard Test Method for Sulfur in Light Liquid Petroleum Hydrocarbons by Gas Chromatography with Sulfur Chemiluminescence Detection