The discrimination of various chemical compounds is generally impossible by using a single tin dioxide-based gas sensor. This research is focused on the development of a hybrid micro-system to get a sensitive and selective portable device for the detection of volatile organic compounds (VOC) in the air. Thus, micro-fabrication technology has been applied to the development of a gas chromatographic micro-column. This system of separation will be positioned upstream of the gas sensor. In this paper, a complete description of the GC micro-column and of the prototype's architecture is given. The gas sample was formed by a gas mixture of benzene, toluene and two isomers of xylene eluted in synthetic air. This prototype, beyond its small size and its great chemical discrimination, provides fast responses and offers best results with very low temperatures of the GC micro-column.