Chemistry of Small Organic Molecules on Snow Grains: The Applicability of Artificial Snow for Environmental Studies
| Authors | |
|---|---|
| Year of publication | 2011 |
| Type | Article in Periodical |
| Magazine / Source | Environmental Science & Technology |
| MU Faculty or unit | |
| Citation | |
| Doi | http://dx.doi.org/10.1021/es104095g |
| Field | Organic chemistry |
| Keywords | Photochemistry; ice; snow; dibenzyl ketone |
| Description | The utilization of artificial snow for environmentally relevant (photo)chemical studies was systematically investigated. Contaminated snow samples were prepared by various methods: by shock freezing of the aqueous solutions sprayed into liquid nitrogen or inside a large walk-in cold chamber at –35 oC, or by adsorption of gaseous contaminants on the surface of artificially prepared pure or natural urban snow. The specific surface area of artificial snow grains produced in liquid nitrogen was determined using adsorption of valerophenone (400–440 cm2 g–1) in order to estimate the surface coverage by small hydrophobic organic contaminants. The dynamics of recombination/dissociation (cage effect) of benzyl radical pairs, photochemically produced from 4-methyldibenzyl ketone on the snow surface, was investigated. The initial ketone loading, c = 10(-6)–10(–8) mol kg(–1), only about 1–2 orders of magnitude higher than the contaminant concentrations commonly found in nature, was already well below monocoverage. |
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