Revisiting gas sampling and analysis with microtechnology: Feasability of low cost handheld gas chromatographs

In this paper, we report the feasibility of handheld systems that can both sample gas for further laboratory analysis as well as provide first field analysis by gas chromatography. In particular the systems include micro silicon preconcentrator chips that enable concentration of Volatile Organic Compounds (VOCs) by a factor of 1000 for sampling durations smaller than 1 minute, as well as micro silicon thermal conductivity detector with a limit of detection in the parts-per-million level. Regarding sampling, the system developed here is compared to state of the art technique using sorbent tube and thermodesorption: comparable results are obtained on a 500 ppb BTEX (Benzene Toluene Ethylbenzene, Xylene) mixture. Regarding analysis, the separation and detection of VOCs down to 20 ppb is demonstrated, without the need of a carrier gas cylinder. Such systems, compatible with low cost development in the future, could find applications in the consumer market for air pollution monitoring.