High Throughput and Rapid Response Gas Chromatography Mr Phillip James & Dr Mark Landon

Have Large Cumbersome Air Blown Gas Chromatography Ovens Had Their Day? Since the late 50’s, conventional gas chromatographs (GC) have been designed in much the same way, with a heated circulating air oven for the column and block heater ovens for the injector and detector. Evolutionary development of the column oven has been influenced by the improvement in column technology from the original large diameter packed columns to todays small bore wall coated capillary columns with their impressive separation capabilities. Current GC column ovens have large stirring fans, high power heaters, multiple skin chambers, forced air cooling and sophisticated electronics to control the heating and cooling cycles.

The last ten years has seen the commercial development of Fast GC systems which dispense with the traditional air blown column oven altogether and heat the column either directly or with very closely coupled heaters along the length of the column. Fast GC can be described as any GC, which performs the same analysis as conventional GC in a reduced time whilst retaining the required resolution. This not only includes the actual sample analysis, but also the cool-down, hence total cycle time. Typically Fast GC enables a 5 to 10 fold reduction of analysis time, with similar enhancements for the cool-down.

These low thermal mass Fast GC systems heat close to the minimum mass possible and therefore can heat and cool the column at rates way beyond the capabilities of conventional GC ovens. The improved heating and cooling rates (Figure 1) achieve vastly reduced cycle times using much less energy, increasing the throughput of a GC, hence, reducing the cost and energy consumed per sample.