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提供精准的源解析信息，烹饪源有机气溶胶对有机气溶胶的贡献尤为显著，尤其在城市环境中。然而离线测量的时间分辨率较低，限制了其在解析示踪数据、烹饪排放的日变化特征以及氧化过程时的应用效能。本研究采用在线热解吸气溶胶气相色谱-质谱联用仪（online thermal desorption aerosol gas chromatography and mass spectrometry, TAG），在中国常州某城市点位对细颗粒物（fine particulate matter, PM2.5）中的有机分子标志物开展监测。本研究以每2小时的频率测定饱和脂肪酸（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，以此探究城市环境中不饱和脂肪酸的时间变化规律及其氧化分解特征。