Department of Analytical Environmental Chemistry, Centre for Environmental Research UFZ, Leipzig-Halle, Permoserstraße 15, Leipzig, D-04318, Germany.
Environ Sci Process Impacts. 2018 Jan 24;20(1):98-104. doi: 10.1039/c7em00495h.
We have extended a recently published toxicokinetic model for fish (TK-fish) towards the oral up-take of contaminants. Validation with hydrophobic chemicals revealed that diffusive transport through aqueous boundary layers in the gastro-intestinal tract and in the blood is the limiting process. This process can only be modelled correctly if facilitated transport by albumin or bile micelles through these boundary layers is accounted for. In a case study we have investigated the up-take of a super hydrophobic chemical, Dechlorane Plus. Our results suggest that there is no indication of a hydrophobicity or size cut-off in the bioconcentration of this chemical. Based on an extremely high, but mechanistically sound facilitation factor we received model results in good agreement with experimental values from the literature. The results also indicate that established experimental procedures for BCF determination cannot cover the very slow up-take and clearance kinetics that are to be expected for such a chemical.
我们已经将最近发表的鱼类毒代动力学模型（TK-fish）扩展到污染物的口服摄入。用疏水性化学物质进行验证的结果表明，胃肠道和血液中的水相边界层中的扩散传输是限制过程。如果不考虑白蛋白或胆汁胶束通过这些边界层的易化转运，则无法正确地对该过程进行建模。在一项案例研究中，我们研究了一种超疏水性化学物质 Dechlorane Plus 的摄入情况。我们的研究结果表明，这种化学物质的生物浓缩过程中没有表现出疏水性或大小截止的迹象。基于一个极高但在机理上合理的促进因子，我们的模型结果与文献中的实验值非常吻合。结果还表明，为了确定 BCF 而建立的实验程序无法涵盖这种化学物质预期的非常缓慢的吸收和清除动力学。
