A gas micropreconcentrator for low level acetone measurements.

The authors designed and manufactured the gas micropreconcentrator in micromachining technology. The structure is 1.68mm thick and has lateral dimensions 2cm by 2cm. It contains the 12cm long channel etched in Si wafer. The channel is covered from the upper side with a glass bonded anodically so as to permit for an easy inspection of the channel during the process of filling it with an adsorbent. At the bottom the Pt heater was deposited, necessary for heating the adsorbent to elevated temperatures during its activation and desorption processes. In the article the authors describe the micropreconcentrator simulations and technology processes together with thermal and preconcentration tests of manufactured structure. A few commercially available adsorbents from Sigma–Aldrich were selected and tested in order to concentrate low levels of acetone. The best concentration factor obtained was 830.