Volume 12, No. 5, October 2012, Pages 892-901 PDF(690 KB)
Characterization of Particulate-Phase High Molecular Weight Mono-Carbonyls (C# > 5) and Dicarbonyls in Urban Atmosphere of Xi’an, China
Wen-Ting Dai1, Steven Sai Hang Ho1,2, Kin-Fai Ho1,3, Jun-Ji Cao1,4
1 Key Laboratory of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, 710075, China
2 Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USA
3 School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
4 Institute of Global Environmental Change, Xi’an Jiaotong University, Xi'an, China
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 PM2.5 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.
High molecular mono-carbonyls; Glyoxal; Methylglyoxal; PM2.5; Xi’an.