Interference effects in sampling particulate nitrate in ambient air

摘要: A laboratory and field study was conducted to evaluate artifact nitrate formation on filter media. The media evaluated included a cellulose acetate, Teflon, five types of glass fiber filters covering pH range from 4.6 9.4. Field studies employed simultaneous sampling using high volume samplers low sampler system providing both respirable (i.e. < 3.5 μm) fraction sample without size segregation. Laboratory interaction clean with nitrogen dioxide nitric acid as possible sources nitrate. influences temperature, relative humidity, time, NH3, ozone SO2 were determined. In 24-h in San Jose Los Alamitos, California, mean values obtained the studied differed by much factor 2.4. Of only Teflon (Fluoropore) provided collection negligible error due gaseous pollutants studied. pH9.3 collected, average, about 10 μg m−3 compared 8.5 true particulate 24h sampling. suggest that is dominant source Nitrogen became substantial presence relatively concentrations ozone.