The chemical composition of inorganic and carbonaceous materials in PM2.5 in Nanjing, China

Abstract

PM 2.5 samples were collected at an urban and a suburban site in Nanjing, China in 2001. They were analyzed for inorganic ions, elemental carbon, organic carbon (OC), water-soluble organic carbon (WSOC), and individual WSOC and nonpolar organic species. Sulfate and organic matter were the two most abundant constituents in these samples. Sulfate accounted for an average of 23% (urban site) and 30% (suburban site) of the identified aerosol mass.Organic matter accounted for an average of 37% (urban) and 28% (suburban) of the identified aerosol mass. WSOC was a significant portion of OC, accounting for about one-third of OC at the urban site and 45% of OC at the suburban site. The suburban-urban gradient in the WSOC/OC ratio also reflected that the aerosol OC was more aged at the suburban location. The correlations of WSOC with sulfate and nitrate suggest that the WSOC fraction was dominated by secondary organics. More than 30 individual WSOC species in the compound classes of organic anions, amino acids, aliphatic amines, and carbohydrates were quantified, accounting for approximately 8% of the WSOC on a carbon mass basis. In addition, 46 individual nonpolar organic compounds in the compound classes of n-alkanes, hopanes, and polycyclic aromatic hydrocarbons were quantified using an in-injection port thermal desorption technique. These nonpolar organic species accounted for less than 7% of the OC on a carbon mass basis. The quantification of individual compounds allowed the identification of major aerosol sources through principal component analysis. Coal combustion, vehicular emissions, secondary inorganic and organic aerosols, and road/sea salt were the major contributing sources to the identified PM 2.5 aerosol mass.

Atmospheric aerosols versus greenhouse gases in the twenty-first century

“…Almost everywhere, do we find a mixture of roughly comparable amounts of organic matter, soluble inorganic species (ammonium, nitrate and sulphate) and insoluble components (mineral dust and soot carbon; Malm et al 1994;Shrestha et al 1997;Zappoli et al 1999;Andreae et al 2002;Putaud et al 2004;Sun et al 2004;Yang et al 2005). The fairly constant proportion of soot carbon-a tracer of combustion and pollution in general-in spite of great variations in absolute aerosol concentrations, suggests that most of the Northern Hemisphere atmosphere is nowadays filled with pollution aerosols, at variable degrees of dilution.…”

Water-soluble Ions in PM2.5 on the Qianhu Campus of Nanchang University, Nanchang City: Indoor-Outdoor Distribution and Source Implications

“…Recently, fine particles (PM 2.5 ) have received much more attention than coarse particle (PM 10 ) (Yang et al, 2005;Feng et al, 2007;Li et al, 2008;Li et al, 2009), as fine particles can travel more deeply into the human lungs, reaching the alveolar region of the respiratory system. They also take along higher contributions of toxic species harming health, higher contributions of light absorption species and light scattering species that affect visibility and the climate more than coarse particles (Kok et al, 2006;Polichetti et al, 2009).…”

Ionic Composition in Aqueous Extracts from PM2.5 in Ambient Air at the City of Cuernavaca, México

“…Also it is observed that the presence of Cl − suggests that this may come from combustion emissions during cooking, coal cars, vegetation burning and incineration [25] [16] The presence of K + in the aqueous extracts from PM2.5 may well have a geological origin, or to be related to emissions from biomass burning [26]. It is likely that for the city of Cuernavaca part of the K + could be originated from soil particles, due to the significant correlation with Ca 2+ [26].…”