Gas chromatographic study of the adsorption of insoluble vapors on water

Adsorption of a Diverse Set of Organic Vapors on the Bulk Water Surface

“…The organic vapors are retained both by absorption into the bulk water phase and adsorption to the gas-water interface whereas other mechanisms such as adsorption at the support/water interface 2 or at the dry support surface are negligible (6,18). The active sites of the support are fully covered with water molecules, and the water film is sufficiently thick for the water surface to be structured as a bulk water surface (6,9).…”

“…The active sites of the support are fully covered with water molecules, and the water film is sufficiently thick for the water surface to be structured as a bulk water surface (6,9). When the organic compounds are present at low concentrations, Henry's law is obeyed and the net retention volume V N of a compound i is given by…”

“…To allow a comparison of the net retention volumes at various water loadings, they have to be normalized to the water surface in the column. To this end, the surface of the highest water loading, A 20% W , can be chosen as reference, and a normalization factor r is defined (6,17),…”

“…To obtain reliable coefficients and to be able to apply Eq. [6] to a broad range of other compounds, the set of compounds in this work was selected to cover a wide range of physico-chemical compound properties (Table 1) (11)(12)(13)(14).…”

“…To date, air-water surface adsorption coefficients, K i watersurf/air , have been measured only for a very restricted set of primarily nonpolar or weakly polar organic compounds (1,(6)(7)(8)(9)(10). These data do not allow a thorough quantification of the electron-donor and -acceptor properties of the bulk water surface.…”