Seasonal distribution of polar organic compounds in the urban atmosphere of two large cities from the North and South of Europe
- 作者：Cé ; sar Oliveira ; Casimiro Pio ; Cé ; lia Alves ; Margarita Evtyugina ; Patrí ; cia Santos ; Virgí ; nia Gonç ; alves ; Teresa Nunes ; Arm ; o J.D. Silvestre ; Finn Palmgren ; Peter Wå ; hlin ; Stu
- 关键词：Urban aerosols ; Polar organic compounds ; Tracers ; Source apportionment
- 刊名：Atmospheric Environment
- 出版年：2007
- 期刊代码：11_13522310
- 类别：env
- 出版时间：September 2007
- 卷：41
- 期：27
- 页码：5555-5570
- 文件大小：441 K
摘要
Polar organic species, including n-alkanols, sterols, anhydrosugars, n-alkanoic acids, n-alkenoic acids and dicarboxylic acids were quantified to typify the composition of fine (PM2.5) and coarse (PM10–2.5) aerosols collected simultaneously at roadside and background sites in Oporto (Portugal) and Copenhagen (Denmark) during separate month-long intensive summer and winter campaigns. As a general trend, both cities exhibit roadside average concentrations higher than their correspondent urban background levels. The polar organics are more abundant in the fine fraction, exhibiting a seasonal pattern with high winter concentrations and low summer loads. Aerosols from both cities showed typical distributions of n-alkanols and n-alkanoic acids in the ranges C12–C28 and C8–C28, respectively. The <C20 homologues, usually attributed to kitchen emissions, vehicular exhausts and microbial origins, dominated the fatty acid fraction. Linear alcohols were mainly represented by higher molecular weight homologues from vegetation waxes. Molecular tracer species for wood smoke (e.g. levoglucosan, mannosan and resinic acids) were found to contribute significantly to the urban aerosol, especially in winter. Ratios between these tracers indicated different biofuel contributions to the atmospheric particles of the two cities. Secondary constituents from both biogenic (e.g. pinonic acid) and anthropogenic precursors (e.g. phthalic and benzoic acids) were detected in both cities and seasons.