Evolution of indoor cooking emissions captured by using secondary electrospray ionization high resolution mass spectrometry
Jiafa Zeng, Zhujun Yu, Majda Mekic, Jiangping Liu, Sheng Li, Gwendal Loisel, Wei Gao, Adrien Gandolfo, Zhen Zhou, Xinming Wang, Hartmut Herrmann, Sasho Gligorovski, and Xue Li.
Abstract: Cooking emissions represent a major source of air pollution in the indoor environment and exhibit adverse health effects caused by particulate matter together with volatile organic compounds (VOCs). A multitude of unknown compounds are released during cooking, some of which play important roles as precursors of more hazardous secondary organic aerosols in the indoor air. Here, we applied secondary electrospray ionization high resolution mass spectrometry for real-time measurements of VOCs and particles from cooking peanut oil in the presence of 300 ppbv of nitrogen oxides (NOx) generated by the gas stove in indoor environment. More than 600 compounds have been found during and after cooking, including N-heterocyclic compounds, O-heterocyclic compounds, aldehydes, fatty acids and oxidation products. Approximately 200 compounds appeared after cooking and were hence secondarily formed products. The most abundant compound was 9-oxononanoic acid (C9H16O3), which is likely the product formed during the heterogeneous hydroxyl (OH) radicals oxidation of oleic acid (C18H34O2) or linoleic acid (C18H32O2). A real-time detection of an important number of organic compounds in indoor air poses a challenge to indoor air quality and models, which do not account for this extremely large range of compounds.