Dicarboxylic acids and related compounds in fine particulate matter aerosols in Huangshi, central China

PM_2.5 (particulate matter with an aerodynamic diameter <2.5 μm) samples were collected in Huangshi, central China, from March 2012 to February 2013 and were analyzed for dicarboxylic acids (diacids) and related compounds (DARCs). Oxalic acid (C₂; 416 ng m⁻³) was the most abundant species, followed by phthalic (Ph; 122 ng m⁻³), terephthalic (tPh; 116 ng m⁻³), succinic (C₄; 70.4 ng m⁻³), azelaic (C₉; 67.9 ng m⁻³), and adipic (C₆; 57.8 ng m⁻³) acids. Relatively high abundances of Ph and tPh differed from the distribution in urban and marine aerosols, indicating contributions from nearby anthropogenic sources. Glyoxylic acid (ωC₂; 41.4 ng m⁻³) was the dominant oxoacid, followed by 9-oxononanoic (ωC₉; 40.8 ng m⁻³) and pyruvic (Pyr; 24.1 ng m⁻³) acids. Glyoxal (Gly; 35.5 ng m⁻³) was the dominant α-dicarbonyl. Highest average concentrations were found for C₂, ωC₂, and C₉ in autumn, for C₄, for Pyr and C₆ in spring, for Ph, ωC₉, and Gly in summer, whereas the lowest values were observed in winter. Seasonal variations and correlation coefficients of DARCs demonstrate that both primary emissions and secondary production are important sources. Principal component analysis of selected DARCs species suggests that a mixing of air masses from anthropogenic and biogenic sources contribute to the Huangshi aerosols. Implications: Both primary emissions and secondary production are important sources of diacids and related compounds in PM_2.5 from Huangshi, central China. Principal component analysis of selected diacids in Huangshi aerosols suggests that mixing of air masses from anthropogenic and biogenic sources contribute to ambient aerosols in central China.