Person-portable gas chromatography: Rapid temperature program operation through resistive heating of columns with inherently low thermal mass properties

As open tubular gas chromatography was becoming widely adopted, the potential to rapidly heat and cool the low thermal mass of an open tubular fused silica column was recognized. Numerous resistive column heating approaches were subsequently described and demonstrated, often with a common objective to focus heating efforts on the column alone, rather than on a large convection oven. Low thermal mass column bundles have been commercially available for about ten years, where insulated wires in close proximity to a coiled open tubular capillary column provide resistive heating. Before this, person-portable gas chromatographs either operated isothermally at relatively low temperatures or at ambient temperature to lessen power demands, but several person-portable gas chromatography–mass spectrometry (GC–MS) instruments capable of temperature program operation have become available in the past ten years based on this heating method. When low thermal mass heated zones are used, and with a direct GC–MS interface, analysis times of less than 5 min are possible for target compounds having a wide range of volatilities. Previous capabilities in transportable and person-portable gas chromatography instrumentation are reviewed to demonstrate the scale of advancement made possible by the adoption of open tubular columns and low power heating techniques now becoming routinely available. Microcomachined columns which are usually etched in a silicon wafer represent a radical break from the traditional fused silica open tubular column design, and increasing efforts to use this column construction approach are also examined. The developments discussed have introduced the potential to rapidly analyze compounds with a wide volatility range in the field to protect deployed military forces, the health of workers, and the health of the general public.