open access

https://hdl.handle.net/2115/46878

Distributions and diurnal changes of low molecular weight organic acids and α-dicarbonyls in suburban aerosols collected at Mangshan, North China

英語

secondary organic aerosols

2010

Geochemical Society of Japan

Geochemical Journal

44(4)

e17-e22

Aerosol samples were collected at Mangshan in the north of Beijing, China in autumn 2007 and analyzed for α,ω-dicarboxylic acids (C2-C12), ketoacids (ωC2-ωC4, ωC9, pyruvic acid) and α-dicarbonyls (glyoxal and methylglyoxal). Oxalic (C2) acid was found as the most abundant species, followed by succinic (C4) and malonic (C3) acids. Concentrations of most compounds, except for C2 and some other species, were higher in daytime than nighttime, indicating that diacids are produced by photochemical oxidation of organic precursors emitted from anthropogenic sources such as fossil-fuel combustion in Beijing, and are transported to Mangshan area by the northerly wind in daytime. Phthalic acid (Ph) was detected as the 4th most abundant diacid both in daytime and nighttime samples, indicating that anthropogenic sources significantly contribute to the organic aerosols. However, lower adipic (C6)/azelaic (C9) acid ratios in nighttime than daytime suggest that biogenic source makes more contribution to the aerosols in nighttime. Higher ratios of C2/total diacids in nighttime than daytime suggest the aging of aerosols proceed more in nighttime, probably due to the aqueous phase oxidation of biogenic precursors. This study demonstrates that water-soluble organic aerosols are secondarily produced in the vicinity of Beijing by the oxidation of both anthropogenic and biogenic precursors.

学術雑誌論文

Version of Record

1880-5973