Solubility and micelle-water partitioning of polychlorinated biphenyls in solutions of bile salt micelles

Experimental data are presented on the enhanced solubilities and micelle/water partition coefficients of 14 polychlorinated biphenyls (PCBs) in solutions of the bile salts sodium taurocholate (TC) and sodium taurodeoxycholate (TDC) below and above the critical micellar concentration (CMC). Solubilities of PCBs in micellar solutions above the CMC depend linearly on bile salt concentration and the solubility enhancement is up to four orders of magnitude. PCB partition coefficients (log Kmw) are independent of bile salt concentrations and are systematically higher in solutions of TDC than in solutions of TC, ranging from 4.26 to 6.24 and from 3.89 to 5.89 respectively. 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 correlation between log Kow and log Kmw is non-linear.