Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.chemosphere.2005.04.082
Title (Primary) Determination of molar absorption coefficients of organic compounds adsorbed in porous media
Author Ciani, A.; Goss, K.U.; Schwarzenbach, R.P.
Source Titel Chemosphere
Year 2005
Department AUC
Volume 61
Issue 10
Page From 1410
Page To 1418
Language englisch
Abstract The kinetics of direct photochemical transformations of organic compounds in light absorbing and scattering media has been sparsely investigated. This is mostly due to the experimental difficulties to assess the major parameters: light intensity in porous media, the reaction quantum yield and the molar absorption coefficient of the adsorbed compound, εi(λ). Here, we propose a method for the determination of the molar absorption coefficient of compounds adsorbed to air-dry surfaces using the Kubelka–Munk model for the description of radiative transfer. To illustrate the method, the molar absorption coefficients of three compounds, i.e. 4-nitroanisole (PNA), the herbicide trifluralin and the flame retardant decabromodiphenyl ether (DecaBDE), were determined on air-dry kaolinite. The measured diffuse reflectance spectra were evaluated with the Kubelka–Munk model and with previously determined Kubelka–Munk absorption and scattering coefficients (k and s), for kaolinite. For all compounds the maximum absorption band was found to be red shifted and the corresponding εi(λ) values were significantly greater than those determined in solvents. Together with the absorption and scattering coefficient of the medium, the measured εi(λ) can be used to determine the quantum yield of the photochemical reaction in this medium from experimentally determined reaction kinetics.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=3256
Ciani, A., Goss, K.U., Schwarzenbach, R.P. (2005):
Determination of molar absorption coefficients of organic compounds adsorbed in porous media
Chemosphere 61 (10), 1410 - 1418 10.1016/j.chemosphere.2005.04.082