|Tittlemier, S.A., Braekevelt, E., Halldorson, T., Reddy, C.M., and Norstrom, R.J., Vapour pressures, aqueous solubilities, Henry's Law constants, and octanol/water partition coefficients of a series of Mixed Halogenated Dimethyl Bipyrroles., Chemosphere, 2004; v57, 1373-1381.|
Basic physical–chemical properties of five bromine and chlorine containing mixed halogenated dimethyl bipyrroles (HDBPs) were determined using established methods. Subcooled liquid vapour pressures , aqueous solubilities (Sw,25), and octanol/water partition coefficients (Kow) were determined using the gas chromatography-retention time, generator column, and slow-stirring methods, respectively. Henry’s Law constants (H25) were estimated using experimentally-derived and Sw,25 data. Values of all four properties were generally similar to those reported for other polyhalogenated aromatic compounds [ Pa; Sw,25 = (1.0–1.9) × 10−5 g/l; log Kow=6.4–6.7; H25 = 0.0020–0.14 Pa m3/mol]. The effect of replacing a chlorine with a bromine atom significantly decreased ( (# bromine atoms) − 2.643, p < 0.01) and H25 (log H25 = −0.508 (# bromine atoms) + 0.394, p < 0.02). There were no significant effects of bromine/chlorine substitution on Sw,25 or Kow. A simple Level I equilibrium partitioning model predicted the environmental behaviour of HDBPs to be similar to a tetrabrominated diphenyl ether. Only slight differences in behaviour amongst HDBP congeners were predicted since substitution of a bromine for a chlorine (Cl/Br substitution) atom had less effect than H/Cl or H/Br substitution on , Sw,25, H25, and Kow.