Atmospheric aerosols have adverse impacts on human health and rank among the main drivers of anthropogenic climate change. Further data from field and laboratory experiments are needed to increase our understanding of aerosol and cloud processes and the quality of their parameterizations in global climate models. Mass spectrometry (MS) has become an important tool in real-time detection and chemical analysis of aerosol particles. An emerging ionization technique in aerosol research is chemical ionization. Chemical ionization is a highly selective, soft ionization method that utilizes the reactivity of the analytes towards the reagent ion to ionize molecules. A high-resolution time-of-flight CIMS (HRToF-CIMS) with a recently developed Filter Inlet for Gases and Aerosols (FIGAERO) will be deployed for both gas and particle molecular composition measurements during this PhD project. The topic of her PhD project is the investigation and analysis of atmospheric organic compounds, their sources and physicochemical properties during aging processes. Laboratory experiments at the AIDA aerosol and cloud chamber at IMK-AAF (https://www.imk-aaf.kit.edu/73.php ) as well as field deployments will be carried out using FIGAERO-CIMS during this project.