Measurement of the semi-volatile component of Dissolved Organic Matter in Snow from the Alps by Thermal Desorption-Proton Transfer Reaction-Time of Flight- Mass Spectrometry

Abstract

Aerosols are small liquid or solid particles suspended in air or gas, or in this case in the atmosphere. Aerosols have a significant impact on climate and are one of the main causes of uncertainty in climate models. Snow samples were collected from the Austrian alps from Febrary 8 until March 18, 2017 to research dissolved organic matter (DOM) originating from deposition of atmospheric aerosols. In this study a novel method was further developed to study DOM using Proton Transfer Reaction-Mass Spectrometry in combination with thermal desorption. The measurements were done at different settings to be able to get nuanced results and to further develop the method. The concentrations found were linked with available meteorological data. The results show that the concentration of organic matter increases in periods with no snow and decreases sharply with fresh snow. A positive correlation was also found between atmospheric pressure and concentration of organic material. Especially pinonic acid and some related ions showed clear correlations.