Scientists of the European countries with the help of several mass spectrometers and cameras with ozone and biogenic volatile organic substance was able to create the aerosol, similar to atmospheric, and the first to study the reactions occurring in the particles. It turned out that over time, due to the interaction with the active oxygen compounds in the particles, chemical reactions occur and they can become a source of formic acid. The results of a study published in the journal Science Advances.
Scattering and absorption of sunlight by aerosols in the Earth’s atmosphere and their influence on the physical properties of clouds has a strong impact on the climate of the planet. In the process of oxidation of volatile anthropogenic and biogenic organic substances formed the so-called vsokoochischennaya volatile organic compounds, which play a key role in the formation and growth of aerosol particles. From the point of view of thermodynamics, the condensation of these substances means the irreversible transition of a substance in the form of particles, and hence the decrease in the concentration of organic substances in the gas phase. Due to the limitations of modern methods, is still the study of the processes of aerosol particles of these substances in real time in the atmosphere, was carried out. Therefore, the nature of the ongoing chemical reactions in the particles remains unexplored.
Pospisilova Veronica (Veronika Pospisilova) with colleagues from the Paul Scherrer Institute using mass spectrometry analyzed the aerosol from vsokoochishchenny volatile organic compounds formed by the ozonolysis of biogenic volatile organic compound α-pinene. Time-of-flight mass spectrometer with extractive ionization electrospray helped the researchers to establish the molecular formula included in the composition of aerosol substances when it is continuous type.
To separate the processes of formation of the gas phase, condensation, and reactions of organic compounds in aerosol particles, the researchers conducted three experiments in the Teflon chamber. They entered into the dark chamber of about 30 ppb (parts billion by volume) of α-pinene and excess of ozone, corresponding to conditions of the atmosphere over the Finnish forest. In such conditions, the aerosol formed quickly and with minimal loss of vapor on the chamber walls. The reaction mixture was not touched for 12 hours, maintaining only the desired pressure.