Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/7007
Title: Summer and winter variations of dicarboxylic acids, fatty acids and benzoic acid in PM₂.₅ in Pearl Delta River Region, China
Authors: Ho, KF
Ho, SSH
Lee, SC 
Kawamura, K
Zou, SC
Cao, JJ
Xu, HM
Keywords: Atmospheric chemistry
Concentration (composition)
Molecular analysis
Organic acid
Photochemistry
Photodegradation
Solubility
Summer
Winter
Issue Date: 11-Mar-2011
Publisher: Copernicus GmbH
Source: Atmospheric chemistry and physics, 11 Mar. 2011, v. 11, no. 5, p. 2197-2208 How to cite?
Journal: Atmospheric chemistry and physics 
Abstract: Ground-based PM₂.₅ samples collected at four different sites in Pearl River Delta region (PRD) during winter and summer (from 14 December 2006 to 28 January 2007 in winter and from 4 July to 9 August 2007 in summer) were analyzed for 30 water-soluble organic species, including dicarboxylic acids, ketocarboxylic acids and dicarbonyls, nine fatty acids, and benzoic acid. Molecular distributions of dicarboxylic acids demonstrated that oxalic acid (C₂) was the most abundant species followed by phthalic acid (Ph) in PRD region. The concentrations of total dicarboxylic acids ranged from 99 to 1340 ng m⁻³, with an average of 438 ± 267 ng m⁻³ in PRD. The concentrations of total ketocarboxylic acids ranged from 0.6 to 207 ng m⁻³ (43 ± 48 ng m⁻³ on average) while the concentrations of total α-dicarbonyls, including glyoxal and methylglyoxal, ranged from 0.2 to 89 ng m⁻³, with an average of 11 ± 18 ng m⁻³ in PRD. The total quantified water-soluble compounds (TQWOC) (organic carbon) accounted for 3.4 ± 2.2% of OC and 14.3 ± 10.3% of water-soluble OC (WSOC). Hexadecanoic acid (C[sub 16:0]), octadecanoic acid (C[sub 18:0]) and oleic acid (C[sub 18:1]) were the three most abundant fatty acids in PRD. The distributions of fatty acids were characterized by a strong even carbon number predominance with a maximum (C[sub max]) at hexadecanoic acid (C[sub 16:0]). Ratio of C[sub 18:1] to C[sub 18:0] acts as an indicator for aerosol aging. In PRD, an average of C[sub 18:1]/C[sub 18:0] ratio was 0.53 ± 0.39, suggesting an enhanced photochemical degradation of unsaturated fatty acid. Moreover, the concentrations of benzoic acid ranged from 84 to 306 ng m⁻³, (165 ± 48 ng m⁻³ on average), which can be emitted as primary pollutant from motor vehicles exhaust, or formed from photochemical degradation of aromatic hydrocarbons. Seasonal variations of the organic specie concentrations were found in the four sampling cities. Higher concentrations of TQWOC were observed in winter (598 ± 321 ng m⁻³) than in summer (372 ± 215 ng m⁻³). However, the abundances of TQWOC in OC mass were higher in summer (0.9–12.4%, 4.5 ± 2.7% on average) than in winter (1.1–5.7, 2.5 ± 1.2% on average), being consistent with enhanced secondary production of dicarboxylic acids in warmer weather. Spatial variations of water-soluble dicarboxylic acids were characterized by higher concentrations in Hong Kong and lower concentrations in Guangzhou (GZ)/Zhaoqing (ZQ) during winter whereas the highest concentrations were observed in GZ/ZQ during summer. These spatial and seasonal distributions are consistent with photochemical production and the subsequent accumulation under different meteorological conditions. (See Article file for details of the abstract.)
URI: http://hdl.handle.net/10397/7007
ISSN: 1680-7316
EISSN: 1680-7324
DOI: 10.5194/acp-11-2197-2011
Rights: © Author(s) 2011. This work is distributed under the Creative Commons Attribution 3.0 License.
Appears in Collections:Journal/Magazine Article

Files in This Item:
File Description SizeFormat 
Ho_summer_winter_variations.pdf578.65 kBAdobe PDFView/Open
Access
View full-text via PolyU eLinks SFX Query
Show full item record

SCOPUSTM   
Citations

39
Last Week
0
Last month
0
Citations as of Aug 17, 2017

WEB OF SCIENCETM
Citations

35
Last Week
0
Last month
1
Citations as of Aug 21, 2017

Page view(s)

153
Last Week
0
Last month
Checked on Aug 20, 2017

Download(s)

17
Checked on Aug 20, 2017

Google ScholarTM

Check

Altmetric



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.