Benzene and xylene detection by absorbance in the range of 10–100 ppb application: Quality of indoor air

In the framework of a French Joint program COVADIS, an innovative system is developed for the simultaneous detection of benzene, toluene and xylenes in indoor air. The present work is focused on the benzene and xylene detection. The detection is based on absorbance measurements over the 250 nm-300 nm spectral range with a cooled and uncooled spectrophotometer. The prototype includes an exposure chamber, which contains five sensors. The sensors are nanoporous disks, whose pore sizes are tailored to efficiently entrap the targeted pollutants. 20 ppb of benzene and 10 ppb of m-xylene have been successfully detected within 40 min of exposure.