Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.chemosphere.2016.11.029
Title (Primary) Isotope fractionation of benzene during partitioning – Revisited
Author Kopinke, F.-D.; Georgi, A.; Imfeld, G.; Richnow, H.-H.
Journal Chemosphere
Year 2017
Volume 168
Page From 508
Page To 513
Language englisch
Keywords Isotopic fractionation; Partitioning; Solvent extraction; Evaporation; Diffusion; Solute-solvent interactions
UFZ wide themes RU3;

Isotope fractionation between benzene-D0 and benzene-D6 caused by multi-step partitioning of the benzenes between water and two organic solvents, n-octane and 1-octanol, as well as between water and the gas phase, was measured. The obtained fractionation factors αH = KH/KD are αH = 1.080 ± 0.015 and αH = 1.074 ± 0.015 for extraction into n-octane and 1-octanol, respectively, and αH = 1.049 ± 0.010 for evaporation from aqueous solution. The comparison of solvent- and gas-phase partitioning reveals that about 2/3 of the driving force of fractionation is due to different interactions in the aqueous phase, whereas 1/3 is due to different interactions in the organic phase. The heavy benzene isotopologue behaves more ‘hydrophilically’ and the light one more ‘hydrophobically’. This synergistic alignment gives rise to relatively large fractionation effects in partitioning between water and non-polar organic matter. In contrast to a previous study, there is no indication of strong fractionation by specific interactions between benzene and octanol.

Partitioning under non-equilibrium conditions yields smaller apparent fractionation effects due to opposite trends of thermodynamic and kinetic fractionation parameters, i.e. partition and diffusion coefficients of the isotopologues. This may have consequences which should be taken into account when considering isotope fractionation due to sorption in environmental compartments

Persistent UFZ Identifier
Kopinke, F.-D., Georgi, A., Imfeld, G., Richnow, H.-H. (2017):
Isotope fractionation of benzene during partitioning – Revisited
Chemosphere 168 , 508 - 513