High sensitivity three-stage microfabricated preconcentrator-focuser for micro gas chromatography

The results of a high sensitivity three-stage microfabricated preconcentrator-focuser (/spl mu/PCF) for a micro gas chromatograph (/spl mu/GC) that can provide real-time monitoring for a quantification and identification analysis of complex organic vapor mixtures are presented. The device consists of a thick Si microheater loaded with graphitized carbon adsorbents and sealed with a Si micromachined cover plate. This three-stage device has effectively extended the detection range of the compounds to cover up to four orders of magnitude in volatility. In addition, the dead volume, thermal mass, heating efficiency, and pressure drop of the single-stage /spl mu/PCF are improved significantly in the three-stage /spl mu/PCF and thus increase the device performance substantially. We demonstrate that thirty common organic vapors are well separated and desorption peak widths are all within 2.05 s.