Analyze Hydrocarbon Impurities in 1,3-Butadiene with an Agilent J&W GS-Alumina PT Column

Importance of the Topic

Trace hydrocarbon impurities in 1,3-butadiene can adversely affect polymerization processes in synthetic rubber production. Identifying and quantifying low-level contaminants such as propadiene and alkynes is critical to ensure feedstock quality and consistent product performance.

Objectives and Overview

This study aimed to transfer an established gas chromatographic method from a standard Agilent J&W GS-Alumina column to a GS-Alumina PT column with integrated dual-ended particle traps. Key goals included evaluating selectivity, improving system stability through particle trapping, and assessing the impact of backflushing on analysis time and reproducibility.

Methodology and Instrumentation

Analyses were performed on an Agilent 7890A gas chromatograph equipped with a High Pressure Liquid Injector, split/splitless inlet, six-port valve for backflushing, and flame ionization detector. Two column configurations were compared: a conventional GS-Alumina column (50 m × 0.53 mm i.d., p/n 115-3552) and a GS-Alumina PT column (50 m × 0.53 mm i.d., p/n 115-3552PT) featuring built-in particle traps. A standard gas mixture of 16 hydrocarbon components was analyzed under helium carrier flow (7.5 mL/min) with retention time locking on propylene at 7.907 min. Oven temperature was programmed from 60 °C to 180 °C with staged holds. Sample injections of 0.5 μL were made via HPLI.

• Agilent 7890A GC system
• High Pressure Liquid Injector
• Six-port backflush valve
• GS-Alumina and GS-Alumina PT columns (50 m × 0.53 mm)
• Flame ionization detector
• Helium carrier gas

Main Results and Discussion

The GS-Alumina PT column demonstrated identical selectivity and resolution compared to the standard GS-Alumina column, with baseline separation of all target analytes and maintained propyne resolution from 1,3-butadiene. Backflushing reduced the total cycle time from over 60 minutes to approximately 30 minutes by efficiently removing high molecular weight impurities. Integrated particle traps prevented column-shedding issues, protected valve switching components, and eliminated detector contamination. Reproducibility was confirmed over 250 injections, yielding relative standard deviations below 2.0% for peak areas and below 0.4% for retention times, with no signs of particle-induced artifacts.

Benefits and Practical Applications

This method transfer provides a robust workflow for routine analysis of trace hydrocarbons in 1,3-butadiene, reducing maintenance related to column fouling and connector leaks. The integrated trapping design enhances instrument uptime, simplifies system assembly, and ensures reliable valve-switching operations in quality control and industrial monitoring settings.

Future Trends and Potential Applications

Adoption of PLOT PT columns with integrated traps is expected to expand across other light hydrocarbon analyses, including C1–C4 impurity profiling in petrochemical streams. Future developments may integrate automated valve control, in-line detection coupling (e.g., GC–MS), and IoT-enabled diagnostics for proactive maintenance. High-throughput screening and remote monitoring will further leverage the enhanced stability offered by PT column technology.

Conclusion

The Agilent J&W GS-Alumina PT column effectively replicates the performance of conventional alumina columns while offering significant advantages in system stability, backflush capabilities, and long-term reproducibility. This transition enables efficient, high-confidence analysis of trace hydrocarbons in 1,3-butadiene with minimal method adjustments and improved operational reliability.

References

1. Wang C. Improved Gas Chromatograph Method for the Analysis of Trace Hydrocarbon Impurities in 1,3-Butadiene; Application Note 5991-1499EN; Agilent Technologies, 2012.
2. Anon. Protect Your GC System from PLOT Column Phase Shedding; Brochure 5991-1174EN; Agilent Technologies, 2012.
3. Sasso P. PLOT PT GC Columns with Integral Particle Traps Separate Gases without Particle Shedding; Application Note 5991-2975EN; Agilent Technologies, 2013.