Lydy Michael J, Harwood Amanda D, Nutile Samuel A, Landrum Peter F
Center for Fisheries, Aquaculture and Aquatic Sciences and Department of Zoology, Southern Illinois University, Carbondale, Illinois.
Integr Environ Assess Manag. 2015 Apr;11(2):208-20. doi: 10.1002/ieam.1603. Epub 2015 Jan 6.
Characterizing sediment-associated hydrophobic contaminants is problematic, because assessing the total amount of a compound available for chemical exchange with an organism is difficult. To address this, contaminant concentrations have been normalized for specific sediment characteristics (including organic C content) or the chemical activity has been estimated using passive samplers. Another approach to assess compound availability is to determine the extent of readily desorbed compound using resin extractions of sediment slurries. The present paper reviews the literature that uses Tenax® TA, a 2,6-diphenylene-oxide polymer as an extraction tool to measure bioavailability of hydrophobic organic contaminants in sediment. Some work has assessed the extent of desorption with sequential extractions to characterize the maximum rate and pool sizes for different desorbing fractions of bound contaminant. As such, the rapidly desorbing fraction has been well correlated with the extent of degradation, bioaccumulation, and toxicity of hydrophobic contaminants. A shortcut to measuring the full desorption curve to determine the rapidly desorbing compound is to use a single-point extraction, with 6 h or 24 h extractions being the most common. The Tenax extraction has been shown to be effective with laboratory-spiked sediments, field-collected sediments, laboratory-exposed organisms, field-collected organisms, and studies among laboratories. Furthermore, a literature-based model has described the bioaccumulation of polychlorinated biphenyls from independently measured field-collected sediments. Despite the success of this approach, applying the Tenax method to manage contaminated sediments is limited by the absence of a standard set of conditions to perform the extractions, as well as standard methods for using field sediments.
表征与沉积物相关的疏水性污染物存在问题，因为评估可与生物体进行化学交换的化合物总量很困难。为了解决这个问题，已针对特定沉积物特征（包括有机碳含量）对污染物浓度进行了归一化，或者使用被动采样器估算了化学活性。另一种评估化合物可用性的方法是通过对沉积物浆液进行树脂萃取来确定易解吸化合物的程度。本文综述了使用Tenax® TA（一种2,6 - 二苯醚聚合物）作为萃取工具来测量沉积物中疏水性有机污染物生物有效性的文献。一些研究通过连续萃取评估了解吸程度，以表征结合污染物不同解吸部分的最大速率和库大小。因此，快速解吸部分与疏水性污染物的降解、生物累积和毒性程度密切相关。测量完整解吸曲线以确定快速解吸化合物的一个捷径是使用单点萃取，其中6小时或24小时萃取最为常见。Tenax萃取已被证明对实验室加标沉积物、现场采集的沉积物、实验室暴露的生物体、现场采集的生物体以及不同实验室之间的研究均有效。此外，一个基于文献的模型描述了从独立测量的现场采集沉积物中多氯联苯的生物累积情况。尽管这种方法取得了成功，但将Tenax方法应用于管理受污染沉积物受到限制，原因是缺乏一套进行萃取的标准条件以及使用现场沉积物的标准方法。
