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1985
Book Article
Titel
Measurements of gaseous nitric acid and particulate nitrate
Abstract
Gaseous HNO3 and particulate NO3-anion were measured by high-volume sampling (50-100 l STP/min) on a non-impregnated filter stack, which consists of a PTFE-filter to remove the particles followed by three nylon filters to absorb HNO3. Extracts of all filters are analyzed for NO3-anion either by a colorimetric method or ion chromatography. The overall detection limit (3sigma definition) of the method ranges between 0.02-0.16 ppbv HNO3 and 0.06-0.035 ppbm NO3-anion, respectively. Some studies concerning the adsorption efficiency, artifact formation, interferences and gas-phase HNO3-anion-calibration are reported as well as field comparisons with other techniques. At Juelich, F.R.G. 890 measurements of atmospheric nitrates were performed during 1982-1984. First evaluations of this data set are reported. (IFU)