title: Dicarboxylic acids, ω-oxocarboxylic acids, α-dicarbonyls, WSOC, OC, EC, and inorganic ions in wintertime size-segregated aerosols from central India: Sources and formation processes.
abstract: The size distributions of aerosols can provide evidences for their sources and formation processes in the atmosphere. Size-segregated aerosols (9-sizes) were collected in urban site (Raipur: 21.2°N and 82.3°E) in central India during winter of 2012-2013. The samples were analyzed for dicarboxylic acids (C2-C12), ω-oxocarboxylic acids (ωC2-ωC9), pyruvic acid and α-dicarbonyls (C2-C3) as well as elemental carbon (EC), organic carbon (OC), water-soluble OC (WSOC) and inorganic ions. Diacids showed a predominance of oxalic acid (C2) followed by succinic and azelaic acid whereas ω-oxoacids exhibited a predominance of glyoxylic acid and glyoxal was more abundant than methylglyoxal in all the sizes. Diacids, ω-oxoacids and α-dicarbonyls showed bimodal size distribution with peaks in fine and coarse modes. High correlations of fine mode diacids and related compounds with potassium and levoglucosan suggest that they were presumably due to a substantial contribution of primary emission from biomass burning and secondary production from biomass burning derived precursors. High correlations of C2 with higher carbon number diacids (C3-C9) suggest that they have similar sources and C2 may be produced via the decay of its higher homologous diacids in fine mode. Considerable portions of diacids and related compounds in coarse mode suggest that they were associated with mineral dust particles by their adsorption and photooxidation of anthropogenic and biogenic precursors via heterogeneous reaction on dust surface. This study demonstrates that biomass burning and dust particles are two major factors to control the size distribution of diacids and related compounds in the urban aerosols from central India.
authors.affiliation: Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan. Electronic address: deshmukh@pop.lowtem.hokudai.ac.jp.
authors.forename: Dhananjay K
authors.initials: DK
authors.lastname: Deshmukh
authors.affiliation: Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan. Electronic address: kkawamura@isc.chubu.ac.jp.
authors.forename: Kimitaka
authors.initials: K
authors.lastname: Kawamura
authors.affiliation: School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur 492010, India.
authors.forename: Manas K
authors.initials: MK
authors.lastname: Deb
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere / Q000737:chemistry; D002244:Carbon / Q000032:analysis*; D003998:Dicarboxylic Acids / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D006038:Glyoxylates / Q000032:analysis; D007194:India; D019815:Oxalic Acid / Q000032:analysis; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D003998:Dicarboxylic Acids; D006038:Glyoxylates; D052638:Particulate Matter; D002244:Carbon; D019815:Oxalic Acid; C010038:azelaic acid; C031150:glyoxylic acid
keywords: Biomass burning; Dust particles; Inorganic species; Primary and secondary sources; Size distributions; Water-soluble dicarboxylic acids