Validation of a diffusive sampler for NO2.
A diffusive sampler for NO2, Willems badge, was validated in laboratory experiments and field tests. The collecting reagent for NO2 in the sampler is triethanolamine, and the analysis is based on a modified colorimetric method, the Saltzman method. The analysis was performed by a flow injection analysis (FIA) technique. The sampling rate for the sampler was determined to be 40.0 ml min-1. There was no effect of NO2 concentration or relative humidity on sampling rate, and the influence of sampling time was found to be small. The detection limit was 4 micrograms m-3 for a 24 h sample. The capacity is high enough to allow sampling of 150 micrograms m-3 for 7 days, which is twice the recommended Swedish short-term (24 h) guideline value as a 98-percentile over 6 months. In field tests, the sampler performed well, even at wind speeds higher than 2 m s-1, and at low temperatures. The overall uncertainty of the method was 24%. The sensitivity and capacity of the method also make it suitable for personal sampling for 2-8 h in working environments.
Hagenbjörk-Gustafsson
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National Institute for Working Life, Department of Chemistry, P.O. Box 7654, S-907 13 Umeå, Sweden.
Lindahl
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Levin
J O
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Karlsson
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D000397:Air Pollution / Q000032:analysis*; D004058:Diffusion; D004784:Environmental Monitoring / Q000295:instrumentation*; D006801:Humans; D009585:Nitrogen Dioxide / Q000032:analysis*; D016273:Occupational Exposure; D010083:Oxidants, Photochemical / Q000032:analysis*; D012680:Sensitivity and Specificity; D017132:Workplace
D010083:Oxidants, Photochemical; D009585:Nitrogen Dioxide