Measurement of Temperature Dependence for Vapor Pressures of Seventeen OH-PBDEs and Eleven MeO-PBDEs by Gas Chromatographic Method.

ABSTRACT

Hydroxylated polybromodiphenyl ethers (OH-PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) are emerging organic pollutants. Supercooled liquid vapor pressures (p L) and enthalpies of vaporization (∆vap H) for seventeen OH-PBDEs and eleven MeO-PBDEs were determined by a gas chromatographic technique. p L at 298 K ranged from 0.0173 Pa for 2'-OH-BDE3 to 2.32 × 10(-7) Pa for 3'-OH-BDE154 and they are approximately one order of magnitude smaller than those determined for the counterpart polybrominated diphenyl ethers (PBDEs). ∆vap H was in the range of 76-121 kJ/mol. The temperature dependence of p L was measured by fitting the experimental data with the log(p L/Pa) = a/(T/K) + b equation, and this corresponds to a 50-265 times higher p L value at 0 versus 30°C. Using fundamental quantum chemical descriptors, two quantitative structure-property relationship models (Q cum > 0.935) were developed to estimate p L at any temperature for the additional OH- and MeO-PBDE congeners.