Portable automatic BTX measurement system with microfluidic device using mesoporous silicate adsorbent with nano-sized pores

We have developed a portable automatic measurement system for the detection and identification of aromatic volatile organic compound (VOC) gases, namely benzene, toluene, and xylenes (BTX), which are air pollutants, by assembling two microfluidic devices, a concentration cell and a detection cell, and peripheral devices. We combined the processes of gas concentration and thermal desorption performed by the concentration cell, with the process of spectroscopic detection performed by the detection cell. We achieved a 50 ppb detection limit for toluene gas as an example of BTX detection in a sampling time of 30 min. We also found that we could obtain better BTX separation by using a highly ordered mesoporous silicate as a gas adsorbent due to a function of its nano-sized pores. As a result, we successfully measured ppm level concentrations of BTX in a mixture gas separately with this device. (C) 2003 Elsevier B.V. All rights reserved.