Henry's law constants for the polychlorinated biphenyls

Abstract

Henry's law constants were predicted from the ratio of the liquid (or subcooled liquid) vapor pressure and aqueous solubility for each polychlorinated biphenyl (PCB) congener. The liquid vapor pressures and aqueous solubilities were derived for each PCB congener by using correlations of Gibbs' free energy of vaporization against gas-liquid chromatographic retention indexes and Gibbs' free energy of solubilization of a liquid against molecular surface area. The predicted values were in fair agreement with experimental values, and the error for these constants was estimated to be a factor of 5 in the temperature range 0.0-40.0 /sup 0/C. For the PCB congeners, Henry's law constants were independent of molecular weight and increased approximately an order of magnitude with a 25.0 /sup 0/C increase in temperature. The average value for Henry's law constants and air-water partition coefficients for the Aroclor PCB mixtures were approximately 4.0 x 10/sup -4/ atm.m/sup 3//mol at 25.0 /sup 0/C.