Supelco™ Gas Purifiers for Total Protection of GC Systems

Importance of the Topic

Gas chromatography (GC) relies on ultrapure carrier and detector gases to maintain column integrity and detector stability. Trace contaminants such as water, oxygen, carbon oxides, and hydrocarbons can degrade stationary phases in packed, capillary, and adsorption columns, shift retention times, and cause peak tailing. Sensitive detectors (FID, TCD, ECD, Hall, GC–MS) also suffer baseline noise and reduced sensitivity when exposed to impurities.

Objectives and Overview of the Article

This bulletin introduces a comprehensive gas purification strategy using Supelco™ products to safeguard GC systems. It reviews the impact of contaminants on various column types and detectors, compares common purification devices, and presents a modular purification system capable of delivering sub-0.1 ppm impurity levels.

Methodology and Instrumentation

The study evaluates the performance of different purifier designs (metal, glass, plastic tubing with various seals) by passing highly purified gas (<1 ppm O2 and H2O) through each device and measuring breakthrough levels. Chromatographic tests monitored column coloration, efficiency loss, retention shifts, and detector baselines when exposed to wet or oxygenated gas streams.

Used Instrumentation

• Supelco Molecular Sieve Drying Tube (5A and 13X/4A variants)
• Supelco High Capacity Heated Gas Purifier (all-metal, 10″ converter tube with gettering material)
• OMI Indicating Purifier (Nanochem® resin-based, visible exhaustion indicator)
• Supelcarb™ HC and Supelpure™ HC Hydrocarbon Traps
• Packard Zero Air Generators (models 1000/1001/2500/2501)

Main Results and Discussion

Tests showed that water and oxygen severely degrade packed and capillary columns, causing brown discoloration, efficiency loss, and retention time drift. Many commercial moisture removers introduce additional impurities via leaks and permeation, especially plastic devices with O-ring seals (up to 100 ppm H2O, 15 ppm O2). Sequentially combining the heated purifier with the OMI purifier achieves ≤ 0.1 ppm O2 and H2O, outperforming certified GC gases. Hydrocarbon traps further enhance detector performance by eliminating baseline noise.

Benefits and Practical Applications

• Prolonged column life and stable retention times
• Improved detector sensitivity and reduced noise
• Elimination of expensive pre-certified gases
• Point-of-use indication of purifier exhaustion
• Modular configuration for multi-instrument installations

Future Trends and Potential Applications

Looking ahead, integration of compact, automated purification modules directly on GC inlets will streamline workflows. Advances in gettering materials and smart exhaustion sensors can provide real-time monitoring. Expansion into high-pressure and ultra-high-purity gas feeds for novel detectors (e.g., micro-GC, portable systems) will further the field.

Conclusion

Comprehensive gas purification using tailored combinations of molecular sieves, heated getter purifiers, indicating sorbents, and hydrocarbon traps can achieve ultralow impurity levels, ensuring optimal GC performance and cost efficiency. Implementing a modular, point-of-use strategy protects columns and detectors while offering visual exhaustion feedback.

References

No literature references were provided in the source document.