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General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. An experimental method is described to determine enhanced solubilities and partitioning of extreme hydrophobics in micellar systems. Experimental data are presented on the enhanced solubilities, chemical activity coefficients and micelle/water partition coefficients of 14 polychlorinated biphenyls (PCBs) in solutions of sodium dodecyl sulfate (SDS) below and above the critical micellar concentration (cmc). The method described in this study proves to be highly accurate. Solubility data obtained are in accordance with data from other studies. Experimental micelle/ water partition coefficients turn out to be sufficiently accurate to distinguish between isomers. Solubilities of PCBs in micellar solutions above the cmc depend linearly on SDS concentration, and the solubility enhancement is 2-4 orders of magnitude. PCB partition coefficients (log Kmw) are independent of SDS concentrations in this study and ranged from 4.61 to 6.62. The partitioning behavior of the pertinent extremely hydrophobics between the aqueous and micellar phases is not completely comparable with simple organic solvent/water systems, and the linear correlation between log KO, and log Kmw no longer holds.

Abstract-Most of the accumulation of polychlorinated biphenyls (PCBs) over the food chain can be attributed to contaminant uptake from food. The effect of fatty acid absorption on net uptake and transport fluxes of a selection of 14 PCBs over the organismal gut epithelium has been determined in monolayers of the colon carcinoma cell line Caco-2 as a model system. The thermodynamic fugacity approach and the physiology of enterocyte lipid digestion are combined to investigate gastrointestinal absorption of polychlorinated biphenyls. The resistances of the subsequent transport steps from the apical compartment through the enterocytes to the basolateral compartment were quantified in terms of conductivity parameters. During uptake of PCBs into the enterocytes, the resistance of the aqueous diffusion barrier adjacent to the brush-border membrane is overcome for more than 99% by means of micellar transport. In the interior of the cells, the aquatic cytoplasm compartment also provides an important route of transport to the PCBs with up to three chlorine atoms, but the more hydrophobic PCBs are preferentially transported by triglyceride particles and lipoproteins. Calculated triolein/water partition coefficients, K tri , in general are higher than taurocholate micelle/water, dimyristoylphosphatidylcholine membrane/water and n-octanol/water partition coefficients, K TC , K DMPC , and K ow , respectively. Calculations suggest that the correlation between log K ow and log K tri is nonlinear.

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