Partition coefficients of hydrophobic contaminants in natural water, porewater, and elutriates obtained from dosed sediment: A comparison of methodologies

Abstract

Partitioning of organic contaminants in elutriates, porewater, and lake water was compared using four methods: XAD-4 resin columns, equilibrium dialysis, and centrifugation and filtration with subsequent C-18 reverse phase column separation. In addition, possible changes in partitioning with sediment aging and during bioaccumulation assays were examined. Centrifugation with C-18 separation produced the most consistent partition coefficients. Partition coefficients from filtration and centrifugation methods compared favorably with previously published data. Contaminant partitioning did not change during 96-h exposures in bioassays, and partitioning of contaminants in porewater and elutriates did not follow a linear trend with the amount of sediment aging or manipulation. The contaminant partitioning apparently depends on characteristics of the contaminant as well as contaminant-associated media composition.