Indoors Formaldehydes and Odorous Hydrogen sulfides

H2S is responsible for most of the odor problems assoeiated with brewing and food processing wastewater treatment. Heavier than air, colorless, corrosive, and extremely toxic, it raises serious woikplace health and safety concerns [109], HjS was measured directly by lAMS, which yielded a cahbiation curve with 0.996 R ) and a detection hmit of 0.05 ppm, while the limit of detection (LOD) by conventional MS with El was 100 ppm, due to interference by the isotope. These results demonstrate the possibility not only of measirring odors but also of monitoring the quahty control of irrdoors, foods, industrial fadhties, arrd so orr. 

QMS would be very helpful in determining the amount of specific PFCs present in air [ 114,115]. In 1997, a QMS with an electron-impact ion source was used to measure PFC concentrations. The main disadvantage of this method may be the interference of ion signals due to the high probability of PFC fragmentation. This creates difficulty in quantitative analysis and the situation is further complicated as most of PFCs break into similar fragments. On-site cahbration is essential for analysis with a QMS. Therefore Hamisch et al. [116] employed MS combined with a GC and/or a cryotrap technique for the measurements of CF, SFg, and C2Fg in the atmosphere. 

Comparison with FT-IR Compared with FT-IR, which has quickly become established as a prime analytical method for tracking emission profiles from exhaust systems within the semiconductor industry, the present methodology has both merits and limitations. The MS method may be more sensitive in most cases however, the 

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