Опубликовано: 04.06.2014 Время чтения: 3 минуты 529

The researches figured out in details, why fatty acids, which fall in oxygen in a large amount during the cooking of meat food, remain the aerosol condition in atmosphere for a long time.Christian Pfrang from the Redding University and her colleagues studied the kinetics of methyl oleate monolayers oxidation by ozone at the air-water interface. These experiments simulate the atmospheric degradation of the aerosol formed from surfactants and water droplets.During the experiment, there was developed a method to track the processes occurring directly in the surface monolayer of the aerosol particles, and it was found that the monolayer of methyl esters is destroyed much faster than it was previously assumed on the basis of the half-decay of these compounds in the atmosphere, suggesting that long-chain organic compounds penetrate through atmospheric aerosol droplets, where they are no longer subjected to ozonolysis.
The kinetics of oxidation of complex esters at the air-water interface can give us the important information about aerosol stability reasons, formed by fatty acids or its derivatives. The presence of certain particles in atmosphere can significantly affect the human health, as well as the climate conditions. In accordance with the result of study series about the origin of the third particle of aerosol forming in central London fell into the atmosphere due to the cooking - these aerosol particles of smog are largely represented by oleic acid and its derivatives, and the acid itself with its esters are formed by frying meat. Lately, the amount of long-chain organic compounds in atmospheric is increased due to the aerosols, because there appear a new source of these substances - vehicles using biofuels, which may also lead to emissions of fatty acids in the environment.

According Pfrang’s words, the study of aerosols is an important task, since the monolayer, located at the surface of aerosol droplets, affects the dimensions of this drop, its stability, the role of such drops in the formation of clouds and thus - in the water cycle on Earth.

Markus Ammann, aerosol chemistry specialist believes that a more realistic model for the study of chemical processes occurring on the surface of aerosol droplets would be the water-air interface. He emphasizes that traditionally the most part of kinetics study’ methods of heterogeneous processes is based on tracking the volume of gas, lost by a multiphase system, and exactly this feature is used to make conclusions about the processes occurring on the surface. He underlines that the new method is very useful for the study of other heterogeneous systems - especially those ones, which still are being disputed, whether the processes occur on the surface or throughout the whole volume.