Fast Simulated Distillation Analysis by Modified ASTM D2887, D7169, D6352, and D7500

Significance of the Topic

The simulated distillation (SimDis) technique is widely used to characterize complex hydrocarbon mixtures by their boiling‐point distributions. Faster, reliable SimDis analyses support petroleum refining, quality control, and compliance with ASTM standards, improving throughput and data consistency in industrial and research laboratories.

Objectives and Study Overview

This application note describes modifications to four established ASTM SimDis methods (D2887, D6352, D7169, D7500) to accelerate analysis times while preserving method performance and compliance. The study evaluates oven temperature ramp rates, boiling‐point distribution accuracy, and overall cycle times for representative gas oil samples.

Methodology

SimDis separates multicomponent blends by elution times corresponding to boiling points. Samples, blanks, and n‐paraffin calibration mixes are run under linear oven temperature ramps. Boiling‐point distributions are generated by correlating retention times to calibrated paraffin markers across specified carbon number ranges. The effect of increasing ramp rates on distribution curves and method limits was systematically assessed.

Instrumentation Used

• PerkinElmer Clarus® 690 Gas Chromatograph
• Programmable on‐column injector
• Wide Range Flame Ionization Detector (WR‐FID) with 0.011″ ID jet
• Helium carrier gas
• TotalChrom® CDS with PKI Dragon® SimDis software

Results and Discussion

• ASTM D2887 (C6–C44): Oven ramps up to 35 °C/min remained within boiling‐point distribution limits, reducing runtime without significant resolution loss.
• ASTM D6352 (C10–C90) and D7169 (C9–C100): Ramps up to 25 °C/min met method specifications; higher rates caused exceedance of QC limits due to peak broadening.
• ASTM D7500 (C8–C110): Extended range required longer hold times to elute high‐boiling species; optimized ramping preserved distribution accuracy.
• The Clarus 690 GC’s rapid cooling (430 °C to 30 °C in <3 min) and injector pre‐rinse further minimize total cycle time.

Benefits and Practical Applications

• Up to 50 % reduction in cycle times boosts lab throughput.
• Maintained compliance with four ASTM SimDis standards.
• Wide dynamic range WR‐FID eliminates manual range switching and enhances sensitivity.
• Enhanced cooling capabilities reduce cryogen usage and operational costs.

Future Trends and Opportunities

• Integration of advanced detectors (e.g., micro‐FID, mass spectrometry) for improved specificity.
• Automated method optimization using machine learning to tailor ramp profiles.
• Broader adoption of rapid SimDis in bio‐fuel and renewable feedstock analysis.
• Development of standardized high‐throughput workflows for real‐time process monitoring.

Conclusion

Modified SimDis methods on the Clarus 690 GC with WR‐FID deliver significant reductions in analysis time while preserving ASTM standard compliance and data quality. Optimized temperature ramping, rapid oven cool‐down, and advanced detection enable high‐throughput, cost‐effective boiling‐point distribution analyses.

References

ASTM D2887, D6352, D7169, D7500 simulated distillation standard methods.