台北都會區大氣氣膠所含正烷類之特性

Gaseous and Particulate n-alkanes in the Taipei Aerosol

林紫嵐(Suzan Lin) ； 王秋森(Chiu-Sen Wang)

《中華公共衛生雜誌》 18卷2期 (1999/04) Pp. 167-175

https://doi.org/10.6288/CJPH1999-18-02-09

摘要

本研究重點在於探討台北都會區大氣中氣相及微粒相C15-C36正烷類之濃度分布形態。由於正烷類依不同污染源而呈現不同的整體特性，因此可利用其整體特性探討大氣有機成分組成的可能來源與季節性變異。本研究使用Model PS-1 PUF採樣器，以石英纖維濾紙收集總懸浮微粒，並在濾紙下游以PUF及XAD-2吸附氣相中的半揮發性有機成分。從1996年六月起至1997年三月止，每季進行五至六天的密集採樣。每一樣本採集24小時。採樣地點為環保署空氣品質監測站中山測站。採得樣本用CH2Cl2溶劑在索氏萃取器中進行萃取後，以GC/FID做定性及定量分析。研究結果顯示，採樣期間台北都會區大氣中微粒相與氣相的正烷類總濃度範圍分別爲9.4~236.89ng/立方公尺地0.27~5.38μg/立方公尺。微粒相正烷類的總濃度隨季節而有顯著變化，以秋季為最低。正烷類之氣相／微粒相濃度比隨氣溫及碳數而改變。根據微粒排放源的追蹤指標，台北都會區四季的氣懸微粒樣本顯示有大量來自汽機車排放的化石燃料燃燒廢氣的人為衝擊。

關鍵字

大氣中懸浮微粒 ； 正烷類 ； 整體特性 ； 氣相／微粒相分布

並列摘要

The objective of this study is to determine the bulk characteristics of n-alkanes and their vapor/particle partition in the Taipei aerosol. We focused the study on n-alkanes which are semivolatile, nonpolar and stable in chemical behavior, and exist at relatively high concentrations in urban aerosols. Because the bulk characteristics of n-alkanes are origin-specific, the n-alkane profile has been used to identify the origin and to explain seasonal variations in atmospheric organic aerosols. We used a Model PS-1 PUF Sampler (Graseby GMW, Village of Cleves, OH, USA) to collect samples of total suspended particulate and n-alkanes in the gas phase. Particles were collected on quartz fiber filters. Gaseous n-alkanes were adsorbed by PUF and XAD-2 in a cartridge placed downstream of the filter holder in the sampler. In each of the four seasons between July 1996 and March 1997, we conducted an intensive sampling operation lasting 5 to 6 days. Each sample was collected over 24 hours. The sampling site was located in the vicinity of the Taiwan Environmental Protection Administration Chung Shan Monitoring Station. The sample were extracted by CH2CI2 in a Soxhlet apparatus and then analyzed for n-alkanes by gas chromatograph/flame ionization detector (GC/FID). The results of analyses for ambient samples show that the concentration of n-alkanes in the total suspended particulate and in the gas phase ranged from 9.4~236.8 ng/m^3 and 0.27~5.38 μg/m^3, respectively. The concentration of particulate n-alkanes varied with the season, with the lowest concentration appearing in the autumn. The vapor-to-particle ratio of n-alkanes depends on the ambient temperature and the carbon number. The results for distribution profile and other bulk characteristics of n-alkanes in the Taipei aerosol indicate that they mainly came from vehicular emissions.

並列關鍵字

ambient aerosol ； n-alkanes ； bulk characteristics ； vapor/particle partition