Spatial and temporal distribution of atmospheric nitric acid and particulate nitrate concentrations in the Los Angeles area

Atmospheric concentrations of nitric acid, sulfur dioxide, particulate nitrate and particulate sulfate, and estimation of their dry deposition on the urban- and mountain-facing sides of Mt. Gokurakuji, Western Japan

“…The HNO 3 concentration was highest in the summer and lowest in the winter on both sides, although less seasonal variation was observed on the mountainfacing side. Similar seasonal variations with higher concentrations during summer than winter have been observed in other studies (Solomon et al 1992;Hong et al 2002;Khoder 2002;Bari et al 2003). This increase in HNO 3 concentration during summer is thought to be attributable to the increased photochemical reaction of NO 2 with hydroxyl radicals (OH·) during this time (Kitto and Harrison 1992;Fowler et al 1998;Seinfeld and Pandis 1998).…”

PM10and PM2.5Compositions in California's San Joaquin Valley

“…The second channel sampled for ionic species with a flow rate of 10 L/min. In this channel, a single quartz-fiber filter was used to collect samples for deionized distilled water (DDW) extraction and analyses for water-soluble nitrate, sulfate, ammonium, sodium, and potassium, A nitric acid denuder with anodized parallel aluminum plates was installed in the third channel to sample particulate nitrate on a quartz-fiber filter and volatilized nitrate on a nylon-membrane backup filter (Solomon et al, 1992). The fourth channel used a Teflon-membrane filter for mass and trace elements with a flow rate of 10 L/min.…”

“…Of the different California air basins, PM,, chemical characteristics have only been extensively studied in the Los Angeles (L.A.) region (Gray et al, 1988;Solomon et al, 1989Solomon et al, , 1992Chow et al, 19928. The highest PM!, mass and chemical compositions are slmilar in the SJV and in the SoCAB.…”

U.S. National PM2.5Chemical Speciation Monitoring Networks—CSN and IMPROVE: Description of networks

“…Ammonium nitrate artifact (loss), related to nitrate only, is minimized in these networks by the use of a denuder-reactive filter (nylon) pair (Table 5; Solomon et al, 1992, Solomon et al, 2003Hering et al, 2004;Chow et al, 2005b). The denuder removes the gasphase interferences, primarily nitric acid, and the nylon filter captures any nitrate volatilized (HNO 3 ) from the particles during sampling (Solomon et al, 1992, Solomon et al, 2003Hering et al, 2004;Chow et al, 2005b).…”