Aerosols have numerous health risks and contribute to climate change. Therefore, it is necessary to understand their physical and chemical properties as well as their formation processes.

For this purpose, many on-line (time-resolved) and off-line (e.g. particle accumulation on a quartz fiber filter) methods have been established. Time-resolved methods are restricted in their sensitivity due to their lacking or reduced accumulation time. This leads to a more qualitative characterization of particles in lower concentrations. Also, aerosol mass spectrometry is very sensible and thus more labor intensive to install in field campaigns. On the other hand, off-line methods can change sample material due to transport and storage and sample preparation for chromatographic or toxicological analysis is more time-consuming. 

The goal of the EUROSTARS project Ai1-CAS is to bridge the gap between established off-line and on-line techniques. For this an improved TOCA-MS setup is combined with machine learning on the bases of a mass spectra database and REMPI cross sections. The thermal-optical carbon analyzer (TOCA) fractionates and quantifies organic and elemental carbon over a temperature ramp. This system is hyphenated with a time-of-flight mass spectrometer combining quasi-simultaneous 3 ionization techniques: EI (electron ionization), SPI (single photon ionization) and REMPI (resonance-enhanced multiphoton ionization). This setup enables a deep characterization of the organic fractions and comparability to aerosol mass spectrometry. Furthermore, with automated sampling the time resolution of this method can be increased for field measurement.

University of Rostock
Institute of Chemistry
Division of Analytical and Technical Chemistry
Gwen Salkewitz
Albert-Einstein-Straße 27
18059 Rostock (Germany)

Tel.: +49 (0) 381 498 - 6534

gwen.salkewitz@uni-rostock.de