Equilibrium passive sampling methods (EPSMs) allow quantification of freely dissolved contaminant concentrations (C_free) in sediment porewater. Polydimethylsiloxane (PDMS) is a convenient sampling polymer that can be equilibrated in field (in situ) or laboratory (ex situ) sediments to determine C_free, providing reliable compound‐specific PDMS–water partition coefficients (K_PDMS‐water) are available. Polycyclic aromatic hydrocarbons (PAHs) are an important class of sediment contaminants comprised of parent and alkylated homologs. However, application of EPSM to alkylated PAHs is challenged by lack of K_PDMS‐water measurements. Our first objective was to obtain K_PDMS‐water for 9 alkylated PAHs and biphenyls using 3 different PDMS‐coated fibers. Quantitative relationships were then established to define K_PDMS‐water for 18 parent and 16 alkyl PAHs included in the US Environmental Protection Agency's sediment quality benchmark method for benthic life protection based on additive toxic units. The second objective was to compare C_free in porewater obtained using both in situ and ex situ EPSMs at 6 Baltic Sea locations. The results indicated that in situ and ex situ C_free for alkyl PAHs generally agreed within a factor of 3. Further, all sites exhibited additive toxic units <1, indicating that PAHs pose a low risk to benthos. The results extend practical application of EPSMs for improved risk assessment and derivation of porewater‐based remediation goals for PAH‐contaminated sediments. Environ Toxicol Chem 2020;39:2169–2179. © 2020 SETAC

中文翻译：

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用于测量沉积物中母体和烷基化多环芳烃自由溶解浓度​​的原位和异位平衡被动采样的比较。

平衡被动采样方法（EPSM）可以定量分析沉积物孔隙水中自由溶解的污染物浓度（C _free）。聚二甲基硅氧烷（PDMS）是一种方便的采样聚合物，可以在野外（原位）或实验室（非原位）沉积物中进行平衡，以测定C的_游离态，从而提供可靠的化合物特异性PDMS-水分配系数（K _PDMS-water）。多环芳烃（PAHs）是一类重要的沉积物污染物，由母体和烷基化同系物组成。但是，由于缺乏K _PDMS水测量，EPSM在烷基化PAH中的应用受到了挑战。我们的首要目标是获得K使用3种不同的PDMS涂层纤维将_PDMS水用于9个烷基化的PAH和联苯。然后建立定量关系，以定义18种母体PAH和16种烷基PAH的K _PDMS-水，这是美国环境保护局基于附加毒性单位的底栖生物保护沉积物质量基准方法中所包括的。第二个目标是比较在6个波罗的海地区使用原位和异位EPSM获得的孔隙水中的_无C值。结果表明原位和异位C_游离烷基PAHs的含量一般在3倍之内。此外，所有位点的加成毒性单位均小于1，这表明PAHs对便当的危害较低。结果扩展了EPSM的实际应用，以改善风险评估和推导基于PAH污染沉积物的基于孔隙水的修复目标。2020年《环境毒理学》； 39：2169-2179。©2020 SETAC