Fugacity and phase distribution of mirex in Oswego River and Lake Ontario waters

Abstract

The phase distribution of mirex, a hydrophobic toxicant, was examined in Oswego River and Lake Ontario waters. A dynamic headspace method was applied to determine the fugacity and free dissolved concentration of mirex in water. Solvent extraction was used to determine the total and particulate adsorbed concentration. In the water phase, 8% to 22% was free dissolved with the remainder bound to dissolved organic matter. In most cases, the particulate fraction was small. Mirex fugacity increased with water temperature. The partition coefficients of mirex with natural dissolved organic carbon (DOC) were 9 × 10 5 to 1.5 × 10 6, and decreased with increasing DOC concentration. A consideration of binding is suggested in the environmental modeling of hydrophobic compounds.