Guoyuan Hu1, Junying Sun2, Yangmei Zhang 2, Xiaojing Shen2, Yun Yang2

  • 1 School of Electronic Information, Wuhan University, Wuhan 430070, China
  • 2 Key Laboratory of Atmospheric Chemistry, Chinese Academy of Meteorological Sciences, Beijing 100081, China

Received: November 16, 2014
Revised: February 8, 2015
Accepted: April 27, 2015
Download Citation: ||  

  • Download: PDF

Cite this article:
Hu, G., Sun, J., Zhang, Y., Shen, X. and Yang, Y. (2015). Chemical Composition of PM2.5 Based on Two-Year Measurements at an Urban Site in Beijing. Aerosol Air Qual. Res. 15: 1748-1759.


  • Two-year measurements on PM2.5 and their organic and inorganic components.
  • Temporal variations and characterization of chemical species in PM2.5.
  • Chemical compositions of three types of polluted cases were investigated.
  • Neutral and acidic PMs were observed and discussed.



In this study, the daily PM2.5 atmospheric aerosols were collected on quartz and PTFE filters simultaneously from January 2008 to December 2009. Organic carbon (OC) and elemental carbon (EC), water-soluble ions including SO42–, NO3, Cl, NH4+, K+, Ca2+, and Mg2+ were analyzed for the samples. The annual average mass concentration of PM2.5 for PTFE was 79 µg m–3. The OC, SO42–, NO3, NH4+ accounted for about 75 % of PM2.5, and secondary organic carbon (SOC) was estimated about 50% of OC. Monthly averages of SO42–, NO3, NH4+, K+ were maximum in June and minimum in October, but EC, Cl displayed the highest in December and the lowest in July, which is related to the coal-combustion emission from heating. Three groups with high, medium and low PM2.5 concentrations were categorized. SO42–, NO3, OC and NH4+ accounted for 24%, 20%, 21% and 11% of sum of defined components in the high concentration days. In the medium and low concentrations, OC occupied large fractions of defined components. Mass closure was obtained for PTFE, but not for quartz. The PM2.5 mass concentrations on quartz filters were about 50 µg m–3 higher than that on PTFE. The concentrations of water soluble ions on quartz filters were about 60–70% of that on PTFE filters. About 15–30% of PM2.5 was considered as the contribution of water vapor, the artifact of water vapor on quartz filter should be noted in later research works. PM2.5 displayed neutral during the year of 2008 and appeared acidic at the next year according to the calculation of cations/anion, concentration of hydrogen and acidic purity. Carbonaceous aerosols occupied same fractions in neutral and acidic aerosols. While sulfate and nitrate contributed 32% and 21% to PM2.5 for acidic aerosols, and 22%, 17% of PM2.5 from sulfate and nitrate for neutral aerosols.

Keywords: PM2.5; OC; Water-soluble ions; Pollution; Acidity

Share this article with your colleagues 


Subscribe to our Newsletter 

Aerosol and Air Quality Research has published over 2,000 peer-reviewed articles. Enter your email address to receive latest updates and research articles to your inbox every second week.

77st percentile
Powered by
   SCImago Journal & Country Rank

2022 Impact Factor: 4.0
5-Year Impact Factor: 3.4

Aerosol and Air Quality Research partners with Publons

CLOCKSS system has permission to ingest, preserve, and serve this Archival Unit
CLOCKSS system has permission to ingest, preserve, and serve this Archival Unit

Aerosol and Air Quality Research (AAQR) is an independently-run non-profit journal that promotes submissions of high-quality research and strives to be one of the leading aerosol and air quality open-access journals in the world. We use cookies on this website to personalize content to improve your user experience and analyze our traffic. By using this site you agree to its use of cookies.