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B. Lendl:
"Mid-IR quantum cascade lasers for trace gas detection in environmental and process analytical chemistry";
Vortrag: Fritz Feigl Symposium on Analytical Chemistry 2015, Wien (eingeladen); 17.09.2015 - 18.09.2015.

Mid-IR quantum cascade lasers (QCLs) are miniaturized, room temperature operated and tunable light sources ideally suited for gas phase analysis. After a short introduction into the technology and characterization of these lasers three different applications will be shown. A portable set-up for open-path measurements using two pulsed QCLs allows quasi simultaneous scanning of characteristic ro-vibrational lines of NO and NO2 respectively and hence their quantitative analysis. The versatile system was used for in-line process monitoring of NO and NO2 in the ppm concentration range in the flue stack of the coal power plant Dürnrohr as well as for measuring trace gas concentrations (a few ppb) in background locations. The second example concerns the development and application of an on-line measurement system for CS2 in a process stream of Lenzing AG based on quartz enhanced photoacosutic spectroscopy. High selectivity, fast response and sub-ppm sensitivities were achieved using a CW operated QCL. In the last example sensitive detection of H2S in industrial process streams of OMV AG using 2f modulation spectroscopy based on QCLs will be shown.