Frontier Lab MicroJet Cryo-Trap

Importance of the Topic

Cryogenic trapping at the head of a GC column enhances capture and release of volatile and gaseous analytes, dramatically improving sensitivity and separation quality in environmental, food, materials, and forensic analyses.

Objectives and Overview of the Study

The document presents the design and performance of Frontier Lab’s universal MicroJet Cryo-Trap (MJT-1035E), expanding cryo-trapping to multiple GC sample introduction systems beyond proprietary pyrolyzers. Key goals include achieving rapid cooling to ‑196°C, reducing LN2 consumption, ensuring compatibility, and demonstrating analytical applications.

Methodology and Principle

A liquefied nitrogen jet is directed onto a narrow section at the column inlet via a thermal exchange coil and MicroJet tube. Flow rates between 3.5–7 L/min control trap temperature from ‑50°C to ‑196°C. Rapid thermal desorption is performed by terminating the LN2 jet and heating the trap section with GC oven air at rates up to 800 °C/min. Integrated baffles circulate N2 gas to prevent icing and maintain reproducibility.

Instrumental Setup

• MJT-1035E Cryo-Trap with controller providing temperature setpoint via 4-line LCD and buttons.
• LN2 dewar (≥2 L) and N2 cylinder (up to 600 kPa supply).
• Compatible GCs: Agilent, Shimadzu, PerkinElmer, Thermo Fisher, etc.
• Sample introduction devices: Multi-Shot Pyrolyzer (EGA/PY-3030D), headspace sampler, purge & trap units.

Main Results and Discussion

• The system reaches ‑196°C in ~2 min at 7 L/min, using one-third the LN2 of similar traps.
• Light gases (CO2, ethane, propane, butanes) were efficiently cryo-trapped and resolved in a 30 m Ultra ALLOY+-1 column at 40°C isothermal.
• Headspace GC/MS of red wine volatiles (ethanol, ethyl acetate, isoamyl alcohol, etc.) demonstrated clear peak separation and sensitivity.
• Heart-cut pyrolysis GC/MS of a ceramic composite identified plasticizers and pyrolyzates, illustrating automated zone-specific trapping and analysis.

Benefits and Practical Applications of the Method

• Enhanced chromatographic resolution and sensitivity for trace volatiles.
• Variable trapping temperatures permit selective enrichment of compounds with different volatilities.
• Energy-efficient design reduces LN2 consumption and operating costs.
• Universal compatibility and automation enable integration into diverse laboratory workflows.

Future Trends and Applications

Anticipated developments include coupling cryo-trapping with advanced detectors (e.g., high-resolution MS, IMS), integration into fully automated sampling systems, and remote monitoring for field-deployable GC platforms. Further miniaturization and eco-friendly refrigerant alternatives may broaden applications in on-site environmental and clinical testing.

Conclusion

The MJT-1035E universal MicroJet Cryo-Trap offers rapid, reproducible, and economical cryogenic preconcentration of volatile analytes for GC and GC/MS. Its flexible design and low LN2 consumption position it as a valuable tool for enhancing analytical performance across multiple industries.

References

• Japanese Patent JP3290968
• US Patent US6190613 B1