Development of a sampling system for organic aerosols (OAs) and volatile organic compounds (VOCs) in the stratosphere

Volatile organic compounds (VOCs) can be processed in the atmosphere through chemical reactions which generates organic aerosols (OAs). These aerosols have a direct influence on climate and public health. Therefore, understanding the chemical composition of OAs and VOCs is essential for the identification of transformations and the sources of these components. (Leppla et al. 2026; Xie and Laskin 2024)

To achieve a measurement regarding the chemical composition of the organic aerosol fraction as well as the semi volatile fraction, an adequate sampler is needed. A piston pump is used to generate sufficient airflow through a filter onto which the aerosols are deposited. The sampler is self-developed to ensure an ideal flow as well as adequate weight. Therefore, a 3D-printed sampler was developed which is ideally suited for our requirements. On a second airstream a thermal adsorption tube is used to sample the volatile organics. The requirements for the sampling system are low weight and high performance due to the desired application on a weather balloon as well as on a drone which requires both low weight and high performance due to shorter sampling periods and limited carrying capabilities. For a possible weather balloon application. The aim is also to employ a variety of sensors to automate the sampling procedure based on pressure, temperature and height of the balloon or drone.

First field tests were performed to evaluate the capability of the sampling methods. The filters were extracted and analysed using high-performance liquid chromatography coupled with high-resolution mass spectrometry (HPLC-HRMS). The adsorption tubes were analysed using a thermal desorption gas chromatography high resolution mass spectrometer (TD-GC-HRMS). The Orbitrap as a HRMS is used to detect and characterise a wide range of organic compounds using a non-targeted approach. This study aims to achieve a detailed chemical profile of the organic aerosols as well as semi volatile organic species present.

This poster aims to provide an overview of the development process of this novel, lightweight, high-performance sampler, which is suitable for weather balloon measurements to enable sampling under the different and harsh conditions in the stratosphere.

Literaturverzeichnis

Leppla, Denis; Hildmann, Stefanie; Zannoni, Nora; Kremper, Leslie A.; Holanda, Bruna A.; Williams, Jonathan et al. (2026): Comprehensive non-targeted molecular characterization of organic aerosols in the Amazon rainforest. In: Atmos. Chem. Phys. 26 (1), S. 365–390. DOI: 10.5194/acp-26-365-2026.

Xie, Qiaorong; Laskin, Alexander (2024): Molecular characterization of atmospheric organic aerosols: Contemporary applications of high-resolution mass spectrometry. In: TrAC Trends in Analytical Chemistry 181, S. 117986. DOI: 10.1016/j.trac.2024.117986.