Characterization of Particulate-Phase High Molecular Weight Mono-Carbonyls (C# > 5) and Dicarbonyls in Urban Atmosphere of Xi’an, China

Received: December 8, 2011
Revised: February 29, 2012
Accepted: February 29, 2012
Download Citation: RIS|BibTeX|https://doi.org/10.4209/aaqr.2011.12.0228  

Cite this article:
Dai, W.T., Ho, S.S.H., Ho, K.F. and Cao, J.J. (2012). Characterization of Particulate-Phase High Molecular Weight Mono-Carbonyls (C# > 5) and Dicarbonyls in Urban Atmosphere of Xi’an, China. Aerosol Air Qual. Res. 12: 892-901. https://doi.org/10.4209/aaqr.2011.12.0228

ABSTRACT

An analytical method to quantify particulate-phase high molecular weight mono-carbonyls (C# > 5) and di-carbonyls has been developed by adopting 2,4-dinitrophenylhydrazine (DNPH) derivatization followed by high performance liquid chromatography/ultra-violet (HPLC/UV) detection. Satisfactory reproducibility and precision of the measurements were achieved. This method was applied to measure the carbonyls in PM_2.5 collected on quartz-fiber filters, sampled in Xi’an, China, from 2008 to 2009. Nonanaldehyde was the most abundant compound, followed by octanaldehyde, hexanaldehyde and heptaldehyde, accounting for 40%, 20%, 12% and 11% in the total quantified carbonyls. For dicarbonyls, the concentration of methylglyoxal was much higher than that of glyoxal. The seasonal variations of the particulate-phase mono-carbonyls and dicarbonyls were similar to those in the gas-phase, namely winter > autumn > spring > summer (except octanaldehyde). A strong correlation among those carbonyls was observed in winter, resulting from low temperature partitioning, weaker photochemical reaction, and more primary emission sources. In contrast, in summer, vehicle emissions, cooking emissions and photochemical reactions are the major pollution source in Xi’an.

Keywords: PM2.5; High molecular mono-carbonyls; Glyoxal; Methylglyoxal; Xi’an