Sorption of diverse organic vapors to snow

Sorption from air to one snow sample has been measured for a broad set of organic vapors covering a wide range of physicochemical properties. Those results that could be compared to literature values mostly lay in the same order of magnitude. As expected, a fit with the vapor pressure did not reveal a good correlation (R-2 = 0.11). Therefore, the data set was interpreted with a linear free energy relationship, based on intermolecular interactions (van der Waals interactions and hydrogen bond interactions), Although we cannot assign the observed sorption to a specific process (adsorption to the snow crystal surface, incorporation in the solid ice crystal, absorption into a quasi-liquid layer, or grain boundary effects), the model provides a useful tool for the prediction of snow sorption for other compounds: 109 K-i snow surface/air = 0.639 (+/-0.037) log K-i hexadecane/air + 3.38 (+/-0.17) Sigmabeta(i) + 3.53 (+/-0.25) Sigmaalpha(i) - 6.85. The sorption coefficients measured could be described well With the compound parameters used (subscript i), with an R-2 = 0.90.