Use of Medaka and Negligible Depletion Solid-phase Microextraction to Evaluate the Impacts of Aqueous Suspensions of Fullerene on the Bioavailability of Organochlorine Compounds

摘要

Negligible depletion solid-phase microextraction (nd-SPME) together with Medaka bioaccumulation were adopted to study the effects of aqueous suspensions of fullerene (nC60) on the bioavailability of eight organochlorine compounds (OCCs) with logKOW = 3.72-6.96. Nd-SPME study revealed that the freely dissolved concentrations of the studied OCCs were markedly reduced with the presence of nC60. Medaka bioaccumulation study demonstrated that at the kinetic uptake regime, nC60 significantly decreased the bioaccumulation of the high hydrophobic OCCs (logKOW > 6), but slightly enhanced the bioaccumulation of the low hydrophobic OCCs (logKOW < 6). The OCC concentrations in Medaka (Cfish) at the kinetic uptake regime linearly correlated with that in nd-SPME fiber (Cfiber) without nC60 (p = 0.053-0.068, R2 ＝ 0.868-0.896), but this correlation deteriorated with the presence of nC60 (p = 0.271-0.312, R2 ＝ 0.473-0.531). These results suggest that in nC60 suspensions the uptake mechanism of OCCs to Medaka is different from that to nd-SPME fiber. While only the freely dissolved OCCs are available to nd-SPME fiber, both the freely dissolved and the nC60 associated OCCs contributed to the accumulation of OCCs to Medaka.