Characteristics and degradation of organic aerosols from cooking sources

Molecular markers in organic aerosol (OA) provide specific source information on PM2.5, and the contribution of cooking organic aerosols to OA is significant, especially in urban environments. However, the
low time resolution of offline measurements limits the effectiveness when interpreting the tracer data, the diurnal variation in cooking emissions and the oxidation process. In this study, we used online thermal desorption aerosol gas chromatography and mass spectrometry (TAG) to measure organic molecular markers in fine particulate matter (PM2.5) at an urban site in Changzhou, China. The concentrations of saturated fatty acids (sFAs), unsaturated fatty acids (uFAs) and oxidative decomposition products (ODPs) of unsaturated fatty acids were measured every 2 h to investigate the temporal variations and the oxidative decomposition characteristics of uFAs in urban environments

有机气溶胶（organic aerosol, OA）中的分子标志物可为PM2.5提供精准的来源解析信息，烹饪源有机气溶胶对OA的贡献尤为显著，在城市环境中更是如此。然而，离线检测手段的时间分辨率偏低，限制了示踪数据解读、烹饪排放日变化规律及氧化过程解析的有效性。本研究采用在线热解吸气溶胶气相色谱-质谱联用技术（online thermal desorption aerosol gas chromatography and mass spectrometry, TAG），在中国常州某城市站点对细颗粒物（fine particulate matter, PM2.5）中的有机分子标志物开展测定工作。每2小时即可完成一次饱和脂肪酸（saturated fatty acids, sFAs）、不饱和脂肪酸（unsaturated fatty acids, uFAs）以及不饱和脂肪酸的氧化分解产物（oxidative decomposition products, ODPs）的浓度检测，以此探究城市环境中不饱和脂肪酸的时间变化特征与氧化分解特性。