High Sensitivity Micro-Thermal Conductivity Detector for Gas Chromatography

Design, fabrication and testing of a micro thermal conductivity detector (muTCD) with a detection limit of 260 parts per billion (hexane in helium), no excess dead-volume, low power consumption, fast response time (150 musec) and low sensitivity to flow rate is described herein. Significantly, this muTCD is shown to have a linear response and high sensitivity across a 10⁴-fold concentration range; to the best of our knowledge this linearity and sensitivity has not been previously shown for a muTCD. The thermal conduction properties of several configurations are examined to identify their influence on performance.