Measuring the Bioavailability of Two Hydrophobic Organic Compounds in the Presence of Dissolved Organic Matter

Abstract

Bioavailability of benzo[a]pyrene (BaP) and 3,3',4,4'-tetrachlorobiphenyl (TCB) was studied in natural lake water containing dissolved organic matter (DOM). Lake water was diluted to give a dissolved organic carbon (DOC) range of 1 to 20 mg/L. Partition coefficients for the model compounds were assessed at different DOM concentrations and over time with three different methods, namely equilibrium dialysis and reverse-phase and liquid-liquid extraction. In addition, biological partition coefficients were estimated from the difference in the bioconcentration of the model compounds in Daphnia magna in the presence and absence of DOM. Results showed that bioavailability of the model compounds was reduced by the presence of DOM. The equilibrium dialysis method gave the best estimates for bioavailability of the model compounds when compared with biologically determined values. Both the reverse-phase and the liquid-liquid extraction overestimated the bioavailable fraction. The more pronounced overestimation of bioavailable fraction of TCB suggested that the sorption of TCB was not only lower but the interaction was also weaker than that of BaP. Increasing DOM concentration produced lower partition coefficients and the effect seemed to be more pronounced when measured by the reverse-phase and the extraction methods.

The factors controlling the partitioning of polybrominated diphenyl ethers and polychlorinated biphenyls in the water-column of the Pearl River Estuary in South China

“…Significantly positive correlations between POC (mg/g) and log K p existed for both BDE99 and PCB28 (p < 0.001) (Fig. 2), which is consistent with other laboratory data (Akkanen and Kukkonen, 2003). No significant correlations between log K p and other parameters, including salinity, DOC, and BC, were found in the present study.…”

Predicting Bioavailability and Accumulation of Organochlorine Pesticides by Japanese Medaka in the Presence of Humic Acid and Natural Organic Matter Using Passive Sampling Membranes

“…The flasks were kept sealed and shaken gently for 4 d in the dark before medakas were added. Several studies have indicated that short contact time (<24 h) is enough to establish an interaction between DOM and HOC that reduces the bioavailability of the HOC in laboratory test system (2,17,18). The bioavailability here refers to the readily available fraction of OCP, which is in equilibrium with the water surrounding the DOM (19).…”

Naturally present fatty acids as internal calibrants for Fourier transform mass spectra of dissolved organic matter

“…An improved understanding of its composition is also essential to understand how pollutants react with DOM and possibly become less bioavailable due to this interaction (Traina et al 1996;Akkanen and Kukkonen 2003;Gourlay et al 2005). Dissolved organic carbon (DOC) is a significant component of the global carbon cycle, accounting for a pool of active carbon (680 × 10 15 g C) that is approximately equal to that of atmospheric carbon dioxide (Hedges 1992;Eglinton and Repeta 2003).…”