二元酸的污染來源主要為石化燃料及生物質量燃燒等原生性污染，與人為及生物源的有機前驅物的光化反應導致之二次污染。本研究探討受石化產業影響之大氣環境在不同污染時期之氣膠溶解性無機鹽類與二元酸之濃度變異，結果顯示氣膠組成，SO42->NO3或SO42->NH4+之趨勢一直是南台灣大氣氣膠組成之特性。
然而在高污染時期，代表交通排放之NO3-污染源顯著貢獻在氣膠濃度的增量。PM2.5 或PM10 中之二元有機酸總量平均約佔大氣微粒質量濃度0.8－1%的含量。其中氣膠二元有機酸含量以oxalic acid 為最大量。在高污染時期，在PM2.5 或PM10 氣膠二元酸主要轉化成oxalic acid ，其所佔總分析之二元酸的比例，從非高污染時期的69 %，上升至73－80 %，顯示高碳數的二元有機酸在大氣中裂解，最後轉化為二個碳鍵(C2)之oxalic acid 的最終產物。本研究結果，可提供空品模式模擬之參考。 Dicarboxylic acids are ubiquitous in the troposphere and one of important organic matters, resulting from marine pathway, fossil fuel burning, biomass burning, cooking, forest biosource and anthropogenic emissions. This study focused on the concentration variations of water-soluble inorganic species and dicarboxylic acids in aerosol during different air quality -periods. The results reveal the concentration of SO42-always exceeded contents of NO3 and NH4+ within both fine and coarse fractions. However, the increase of NO3-, presenting the traffic emission, was significant during the period of episode. The percentage contribution of dicarboxylic acids in both PM2.5 and PM10 was 0.8-1.0 % by mass. Oxalic acid was the biggest single dicarboxylic acids. During the episode, the transformation percentage of dicarboxylic acids in both PM2.5 and PM10 increased significantly. The percent of oxalic acid in measured dicarboxylic acids raised from 69 % during non-episode to be 73-80 % during episode, indicating the more carbon-bonding dicarboxylic acids decomposed to be 2 carbon-bonding products, oxalic acid during the period of episode. These results can offer the estimation for air quality model application.
