Microtrap interface for on-line mass spectrometric monitoring of air emissions

✍ Scribed by Mitra, Somenath; Feng, Chaohua; Zhang, Lizhong; Ho, Wenpin; McAllister, Gary

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 172 KB
• Volume: 34
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(199905)34:5<478::aid-jms788>3.0.co;2-2

✦ Synopsis

One of the problems in on-line mass spectrometric monitoring of air emissions is that whereas organic pollutants are present at trace concentrations (ppm to ppt levels), background gases such as and may be present at H 2 O CO 2 per cent levels. Moisture in particular is a source of serious interference. A sampling interface that eliminates these interferences but allows the continuous introduction of organics into the mass spectrometer is presented. The interface consists of a micro-sorbent trap (referred to as the microtrap) that selectively traps the organics, and then injects them into the mass spectrometer via rapid thermal desorption with an electric pulse of ¿1 s duration. Continuous (or near-continuous) monitoring is achieved by making a series of desorptions while the air Ñows continuously through the system. The applicability of this approach is demonstrated by monitoring the emissions from a catalytic incinerator.