The Speciated Detection of Gas-phase Organic Peroxy Radicals and Related Intermediates by Proton Transfer Mass Spectrometry

In spite of the importance of organic peroxy radicals in the oxidizing capacity of the atmosphere few techniques exist to monitor them individually, leaving large uncertainties in the understanding of the atmospheric oxidation cycles. This presentation will give an overview of the on-going ERC-advanced project EPHEMERAL focusing on the detection of these radicals using proton transfer mass spectrometry and aiming at monitoring them in ambient air. Current advances in their detection and in that of related intermediates will be presented. The main advantages and limits of the technique will be discussed, in particular the challenges and various strategies for determining the radical absolute concentration (calibrations). While the technique is still being improved, the performances already obtained allow to study new reactions, such as the interactions of the gas-phase radicals with surfaces, which will be also rapidly presented.