Partitioning of chlorinated solvents between pine needles and air

The equilibrium partitioning of tetrachloromethane (CCl4), trichloroethene (C2HCl3), tetrachloroethene (C2Cl4) and 1,1,1-trichloroethane (C2H3Cl3) between the gas phase and both needles and hexane-extractable leaf waxes of Scots pine (Pinus sylvestris L.) was measured at room temperature (20 °C). Needles and wax came to equilibrium with gas-phase concentrations in the range 2.5–1500 mg m−3 within 6 hours. Partition ratios (PR: g m−3 needle/g m−3 gaseous nitrogen) for whole needles were 9, 27, 200 and 10 for CCl4, C2HCl3, C2Cl4 and C2H3Cl3 respectively; for extractable wax the partition ratios were 90, 390, 2100 and 950 respectively. The partition ratios are similar to published data for Norway spruce. There was a linear relationship between log(PR) for whole needles and the octanol-air equilibrium constant, log(Koa), suggesting that the PR depends on the balance between the octanol-water equilibrium constant and aqueous solubility. There was also a linear relationship between log(PR) and boiling point for the 4 chlorinated hydrocarbons studied.