In vitro digestive fluid extraction as a measure of the bioavailability of sediment‐associated polycyclic aromatic hydrocarbons: Sources of variation and implications for partitioning models
In vitro digestive fluid extraction as a measure of the bioavailability of sediment‐associated polycyclic aromatic hydrocarbons: Sources of variation and implications for partitioning models
复制标题
体外消化液提取作为沉积物相关多环芳烃生物利用度的衡量标准：变异来源和对分配模型的影响
DOI：
10.1002/etc.5620170509
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发表时间：
1998
影响因子：
4.1
通讯作者：
L. Mayer
中科院分区：
文献类型：
--
作者：
D. Weston;L. Mayer
为了研究污染物的生物积累机制，并可能更好地量化污染物的生物可用分数，最近提出了用摄食沉积物的消化液体外提取污染沉积物的方法。使用来自巴西多毛类的消化液和六种海洋沉积物对这种方法进行了评估，这些沉积物中既含有添加了放射性标记的多环芳烃(PAHs)，也含有原位污染的未标记的PAHs。各底泥中消化液提取的总污染物比例分别为22%~71%和13%~52%，其中菲和苯并[a]芘所占比例最大。污染物的溶解比例与沉积物的有机碳含量呈负相关。巴西姬松茸消化液对沉积物中多环芳烃的增溶程度与沼虾消化液中多环芳烃的增溶程度高度相关，这似乎是由消化液的表面活性剂性质决定的，而不是由其酶活性决定的。多环芳烃在体外的增溶比例与体内对污染物暴露持续约24小时的增溶比例相似。然而，随着持续暴露，体内消化液中的多环芳烃浓度增加了5倍，这表明消化液在肠道中的滞留时间比沉淀物更长，从而通过顺序消化许多肠道体积积累多环芳烃。这种现象可能会增加污染物在肠道中的逃逸能力，并增加生物积累或毒性的可能性。
In vitro extraction of contaminated sediments using the digestive fluid of a deposit‐feeding polychaete has recently been proposed to study contaminant bioaccumulation mechanisms and perhaps to better quantify the bioavailable contaminant fraction. This approach was evaluated using digestive fluid from the polychaete Arenicola brasiliensis and six marine sediments containing both spiked radiolabeled polycyclic aromatic hydrocarbons (PAHs) and in situ–contaminated unlabeled PAHs. The proportion of total contaminant extracted by digestive fluid from each sediment varied from 22 to 71% and 13 to 52%, for phenanthrene and benzo[a]pyrene, respectively. The proportions of contaminant solubilized were inversely correlated with the sediments' organic carbon content. The extent of PAH solubilization among sediments by A. brasiliensis digestive fluid was highly correlated with that of digestive fluid from the echiuran Urechis caupo and appears to be a consequence of surfactant properties of the fluids rather than of their enzymatic activity. The proportion of PAHs solubilized in vitro was similar to in vivo measurements of solubilization for contaminant exposures lasting about 24 h. However, with continued exposure, in vivo PAH concentrations in the digestive fluid increased fivefold, suggesting that digestive fluid is retained in the gut longer than sediment and thus accumulates PAHs through sequential digestion of many gut volumes. This phenomenon may enhance contaminant fugacity in the gut and increase the potential for bioaccumulation or toxicity.