Department of Environmental Science, Aarhus University, PO Box 358, 4000 Roskilde, Denmark.
Environ Sci Technol. 2012 Oct 2;46(19):10682-9. doi: 10.1021/es301515s. Epub 2012 Sep 10.
In principle, soil bioaccessibility extraction methods are simple dissolution experiments, where the fraction of compounds that is transferred to the extraction medium is measured and considered to be bioaccessible. For hydrophobic organic chemicals (HOCs) such techniques can lead to underestimation of bioaccessibility when the capacity of the extraction medium is insufficient to provide infinite sink conditions for the target compounds. A sorptive bioaccessibility extraction (SBE) method was thus developed and validated, which integrates the key processes of desorption from the matrix and subsequent consumption or depletion. Cyclodextrin was used as a diffusive carrier to enhance desorption from the matrix, while a silicone rod was used as a dominating sink that continuously absorbed the HOC molecules from the cyclodextrin solution. The silicone rod was then solvent extracted and the HOCs measured by GC-MS. For wood soot, the SBE method yielded PAH bioaccessibility estimates that were 3-24 times higher compared to a cyclodextrin extraction without a sink. The study demonstrated that the inclusion of an absorption sink into an established bioaccessibility extraction method (1) is rather simple, (2) can have a major impact on the obtained results, especially for the more hydrophobic compounds and (3) can simplify the analytics.
原则上，土壤生物可给性提取方法是简单的溶解实验，其中测量并认为被转移到提取介质中的化合物分数是生物可给的。对于疏水性有机化学品（HOCs），当提取介质的容量不足以为目标化合物提供无限的汇条件时，这些技术可能导致生物可给性的低估。因此，开发并验证了一种吸附生物可给性提取（SBE）方法，该方法整合了从基质中解吸以及随后的消耗或耗尽的关键过程。环糊精被用作扩散载体，以增强从基质中的解吸，而硅酮棒用作主导的汇，它不断从环糊精溶液中吸收 HOC 分子。然后用溶剂提取硅酮棒，并通过 GC-MS 测量 HOC。对于木煤烟灰，与没有汇的环糊精提取相比，SBE 方法得出的 PAH 生物可给性估计值高 3-24 倍。该研究表明，将吸收汇纳入现有的生物可给性提取方法（1）相当简单，（2）会对获得的结果产生重大影响，特别是对于更疏水性的化合物，（3）可以简化分析。
