Micropacked Column Inlet and FID Adaptor Kits

Importance of the Topic

Micropacked columns with a 1/16" outer diameter deliver high inertness and reduced dead volume, enabling sensitive trace analysis in gas chromatography. Adapting standard capillary GC inlets and FID detectors to these columns expands analytical flexibility and performance.

Objectives and Study Overview

This application note presents adaptor kits for converting Agilent 5890, 6890, and 7890 split/splitless inlets and FID detectors to accommodate 1/16" micropacked columns. Two inlet configurations (split/splitless and on-column injection) and a dedicated FID adaptor are described.

Methodology and Instrumentation

• Standard inlet conversion: Removal of original reducing nut, installation of large-bore reducing nut with integrated Vespel/graphite inlet seal, precise column placement 30–32 mm into the injector, and installation of a deactivated splitless liner.
• On-column injection: Use of a Siltek-treated metal liner guide, marking 101 mm for insertion depth, and controlled torque of 1/4 to 1/2 turn on the nut for optimal sealing.
• FID connection: Fitting a large-bore FID adaptor with 1/4" ferrule, followed by insertion of the 1/16" micropacked column into the FID jet with minimal backfill, tightened by finger and wrench.
• Leak verification: Pressurizing the system with carrier gas and performing electronic leak detection on all fittings.

Used Instrumentation

• Agilent 5890/6890/7890 Gas Chromatographs
• Micropacked Column Inlet and FID Adaptor Kits (Restek cat. #22424–22428)
• 4 mm deactivated splitless glass inlet liner
• Vespel/graphite ferrules and stainless-steel nuts
• Electronic leak detector (Restek cat. #28500)

Main Findings and Discussion

The adaptor kits provide inert, low–dead-volume connections for micropacked columns, preserving analyte integrity and chromatographic resolution. Integrated dual Vespel/graphite seals remove the need for metal washers, reducing adsorption sites. Accurate column depth control ensures reproducible retention times and consistent peak shapes. The FID adaptor delivers direct coupling with minimal dispersion.

Practical Benefits and Applications

• Enhanced sensitivity and reproducibility for trace-level environmental, petrochemical, and pharmaceutical analyses.
• Compatibility of micropacked columns with common Agilent GC platforms.
• Modular design enables rapid kit-based installation and maintenance.
• Reduced downtime through integrated sealing solutions and straightforward leak checks.

Future Trends and Potential Applications

As micropacked columns become more prevalent, future innovations may include higher-temperature materials, further miniaturization, and integration of smart sensors to monitor seal integrity. Automated installation tools and advanced coatings could further streamline method development and enhance durability.

Conclusion

Restek’s micropacked column inlet and FID adaptor kits offer a robust, inert solution for incorporating 1/16" micropacked columns into standard Agilent GC systems. By following precise installation steps and performing thorough leak checks, analysts can achieve high sensitivity, reproducible chromatography, and extended column lifespan.

References

1. Restek Corporation. Micropacked Column Adaptor Kits Installation Manual. 2020.
2. Restek Corporation. Electronic Leak Detector Product Guide. 2020.