Design considerations for a GC×GC system

Experiments in the development of two prototype interfaces for comprehensive multidimensional gas chromatography (GC×GC) have demonstrated some interesting aspects of the interface design that must be considered as researchers try to develop better interface technologies based upon thermal modulation. Studies of injection band structure from cryotrap-based and sorbent-based interfaces demonstrated the effects of cooling times and applied heating pulses on the performance of the interfaces. Additionally, effects of non-optimised positioning of the cryogen addition point for cryogenic interfaces are discussed. Results from direct measurements of Silcosteel cooling times correlated well with breakthrough tails seen in single-stage cryotraps, suggesting that tubing with smaller thermal mass (hence faster cooling times) should perform better when incorporated into the system.