Development and evaluation of a calibration gas generator for the analysis of volatile organic compounds in air based on the injection method.
The development and operational evaluation of a calibration gas generator for the analysis of volatile or ganic compounds (VOC) in air is described. Details of the construction, as well as of the evaluation of the apparatus are presented here. The performance of the test gas generator is validated both by on-line GC analysis of the calibration gas produced and by off-line analysis of adsorptive samples taken from the generated calibration gas. Both, active and passive sampling have been used, and the results demonstrate the excellent accuracy and precision of the generated test gas atmosphere: For the 11 investigated organic compounds (aromatic and halogenated compounds), the found values were in most cases within 5% of the target value with a reproducibility of better than 3% RSD (as determined by the analysis of the sampled adsorbent tubes). Custom made adsorbent tubes were used for active and passive sampling and in both cases were analysed by thermal-desorption GC. Particularly the combination of passive sampling and thermodesorption-GC analysis offers significant advantages over the commonly used active sampling on activated charcoal, followed by CS2 desorption in terms of avoidance of hazardous solvents, potential for automation and improved detection limits. Both sampling techniques are capable for monitoring VOCs at concentrations and under conditions relevant for workplace monitoring.
Rosenberg
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E
Institute of Analytical Chemistry, Vienna University of Technology, Austria. erosen@mail.zserv.tuwien.ac.at
Hallama
R A
RA
Grasserbauer
M
M
D000327:Adsorption; D000393:Air Pollutants / Q000032:analysis*; D000465:Algorithms; D002138:Calibration; D002246:Carbon Disulfide / Q000032:analysis; D002849:Chromatography, Gas; D004784:Environmental Monitoring; D017022:Flow Injection Analysis; D016273:Occupational Exposure / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis*; D015203:Reproducibility of Results
D000393:Air Pollutants; D009930:Organic Chemicals; D002246:Carbon Disulfide