A ready-to-deploy implementation of a microfabricated gas chromatography (GC) system character-ized for detecting hazardous air pollutants (HAPs) at parts-per-billion (ppb) concentrations in complexmixtures has been described. A microfabricated preconcentrator (PC), MEMS separation column withon-chip thermal conductivity detector (SC-TCD), flow controller unit, and all necessary flow and ther-mal management as well as user interface circuitry are integrated to realize a fully functional GC system.The work reports extensive characterization of PC and SC-TCD for target analytes: benzene, toluene,tetrachloroethylene, chlorobenzene, ethylbenzene, and p-xylene. A Limit of Detection (LOD) of ∼1 ngwas achieved, which corresponds to a sampling time of 10 min at a flow rate of 1 mL/min for an ana-lyte present at ∼25 ppbv. An innovative method using flow-manipulation generated sharp injectionplugs from the PC even in the presence of a flow-sensitive detector like a TCD. The GC system iscompared against conventional automated thermal desorption–gas chromatography–flame ionizationdetector (ATD–GC–FID) system for real gasoline samples in simulated car refueling scenario. The GCsystem detected five peaks, including three of the target analytes and required ∼3 orders of magnitudelower sample volume as compared to the conventional system.