Complexity of downy birch emissions revealed by Vocus proton transfer reaction time-of-flight mass spectrometer

Biogenic volatile organic compounds (BVOCs) are known to strongly influence the global climate by affecting various atmospheric constituents such as oxidants and aerosols. Among several BVOCs that emitted continuously into atmosphere, studies have shown up 96% of emissions been missed out current analytical techniques. In this study, we used a Vocus proton-transfer-reaction time-of-flight mass spectrometer (Vocus) characterize quantify from branch downy birch tree at boreal forest site in Hyytiälä, Finland August 2019. During measurement period, were able observe real-time hydrocarbons with 20 carbon atoms oxygenated (OVOCs) 4 oxygen atoms. OVOCs accounted for around 90% total observed largest contribution C 8 H O 3 (0.37 μgg –1 h ; ∼60% total). For first time, diterpenes (C 32 , 36 38 ) tree, although minor quantities (0.1% emissions). late growing season, 10 16 14 contributed ∼7% emissions, while sum 5 15 22 24 ∼3%. The experienced abiotic stress during which might explain unusually high . Standardized emission potentials reported all using two Guenther algorithms. While most fit well either algorithms, certain like could not be explained suggesting other factors besides temperature light. PTR-TOF-MS can help identify diverse range molecules even if minute quantities. detected may important formation secondary aerosols but their implications atmosphere need verified further studies.