A pressure programmable gas chromatography microsystem utilizing motionless Knudsen pump, fiber-integrated optical detector, and silicon micromachined separation column

This paper describes a micro gas chromatography (μGC) system that utilizes three miniaturized components. An optical fiber-based detector is used to monitor the elution peaks of different chemical species through a 25 cm long micromachined separation column. A motionless gas pump based on thermal transpiration is used to transport the analytes in the μGC. Simple pressure programming allows rapid analysis (<;5 min) without compromising the resolution of the lighter analytes. For example, the μGC system is operated at a pumping pressure head of 10.5 kPa for 35 sec to separate lighter analytes (pentane, heptane, and octane); the pumping pressure head is then ramped up to 21.6 kPa to allow rapid detection of heavier analytes (decane, and undecane).