DESIREE&Friends 7: Investigating Gas-phase Organic Peroxy Radicals and Related Compounds with Proton Transfer Mass Spectrometry

by Barbara Noziere (KTH, Royal Institute of Technology)

Tuesday 9 Dec 2025, 15:15 → 16:00 Europe/Stockholm

FB54 (AlbaNova Main Building)

Organic peroxy radicals (RO2) are key intermediates in the oxidation of organic compounds in many aerobic chemical systems such as living organisms, low temperature combustion, and Earth’s atmosphere. For instance, their reactions are increasingly being considered in cancer therapy. In Earth’s atmosphere, they are responsible for the oxidative capacity of the atmosphere and for the formation new aerosol particles of climate importance. But, in spite of their importance in all these chemical systems, few techniques exist that allow to distinguish between different RO2 in complex systems, leading to uncertainties in their chemistry. Chemical ionization and, in particular, proton transfer mass spectrometry is a promising technique for monitoring simultaneously individual RO2 in complex systems such as in ambient air, and is the focus of the on-going ERC-advanced project EPHEMERAL. This presentation will give an overview of the main questions on RO2 chemistry in atmospheric science and of the progress achieved in project EPHEMERAL on the detection of these radicals, of related key compounds, and on the study of their reactions.