土壤中锁定残留芘在体外消化系统中的生物可给性

Oral Bioaccessibility of Bound Residue of Pyrene in Contamination Soils Determined by an in Vitro Gastrointestinal Model

体外消化过程可能导致土壤中憎水有机污染物提取量增加.论文采用3种有机质含量不同的土壤进行体外消化实验,目的在于验证如下假设：土壤中部分锁定残留芘可以在人体消化系统中释放出来,若不考虑这部分贡献,常规提取方式获得的土壤污染浓度可能低估污染土壤口摄风险.研究结果证实：经体外消化的土壤的总芘提取量显著高于未经消化样品,其差别与土壤有机质含量有关.消化液中的胆汁盐是造成锁定残留芘释放的关键成份.在特定范围（2~20mg·mL-1）内,提取效率不受胆汁盐浓度影响.胆汁盐作用下锁定残留芘的释放为一次动力学过程.

The hypothesis tested in this study was that bound residue of pyrene in contaminated soils can be released in human digestive tract, leading to an extra oral exposure risk. Three soils with different organic matter contents were collected and investigated using an in vitro gastrointestinal model. It was demonstrated that a fraction of bound residue of pyrene was mobilized during the digestion, leading to a higher total quantity of pyrene extracted with the pre -digestion than that without the pre -digestion. Among various enzymes used in the gastrointestinal model, bile salt was the sole key component for the mobilization of the bound residue. The efficiency of the mobilization was not affected by the bile salt concentrations within the studied range from 2 to 20mg·mL-1. A first order kinetics fit the process well.