1.1 美国环境保护局（USEPA）针对受多环芳烃（PAHs）污染的沉积物中底栖生物的麻醉模型基于沉积物间隙水或“孔隙水”中溶解的PAHs浓度。本试验方法包括从受多环芳烃影响的沉积物样品中分离孔隙水，去除胶体，以及随后测量孔隙水样品中所需的10种母体多环芳烃和14组烷基化子多环芳烃的溶解浓度。使用固相微萃取（SPME）测定“24种多环芳烃”，然后在选择离子监测（SIM）模式下进行气相色谱/质谱（GC/MS）分析。 提取前引入目标化合物的同位素标记类似物，并用作定量参考。 1.2 较低分子量的多环芳烃比较高分子量的多环芳烃更易溶于水。因此，由于茚[1,2,3-cd]芘的饱和水溶解度从0.2µg/L到31µg/L不等，美国环保局规定的孔隙水中多环芳烃浓度差异很大 萘为000微克/升。该方法可以测量低分子量多环芳烃的微克/升浓度和高分子量多环芳烃的纳克/升浓度。 1.3 如果毒性单位总和（∑TU），美国环保局麻醉模型预测对底栖生物的毒性 c )孔隙水样本中测量的所有“34多环芳烃”的计算值大于或等于1。因此，将单个多环芳烃测量所需的性能极限定义为将产生的单个多环芳烃的浓度 1. / 34 毒性单位（TU）。然而，该方法的重点是10种母体多环芳烃和14组烷基化多环芳烃( 表1 )这贡献了95 % 基于对120个背景和受影响沉积物孔隙水样的分析，确定毒性单元。 3. 消除其余5-6环母体多环芳烃的主要原因是: (1) 这些多环芳烃对孔隙水TU贡献不大，并且 (2) 这些多环芳烃表现出极低的饱和溶解度，这将使这些化合物在孔隙水中的检测变得困难。 该方法可达到所需的检测限，其范围从高分子量多环芳烃的约0.01µg/L到低分子量多环芳烃的约3µg/L。 1.4 该试验方法也可用于测定额外的多环芳烃化合物（例如，霍桑等人所述的5环和6环多环芳烃）。 4. 然而，本标准的用户有责任确定测定多环芳烃的试验方法的有效性，而非本标准中引用的方法 1.1 和 表1 . 1.5 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。 本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 有关具体的危险说明，请参阅第节 9 . 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 该方法直接测定环境沉积物孔隙水样中溶解多环芳烃的浓度。 从环境监管角度来看，该方法很重要，因为它可以实现分析灵敏度，以满足美国环保局麻醉剂模型的目标，从而保护多环芳烃污染沉积物中的底栖生物。使用溶剂萃取的监管方法尚未实现从纳克到毫克/升的宽校准范围，以及纳克/升范围内所需的检测水平。此外，传统的溶剂萃取方法需要大量等分体积（升或更大），使用大量有机溶剂，并过滤以生成孔隙水。这种方法需要存储和处理大量沉积物样品，并在过滤和溶剂蒸发步骤中损失低分子量多环芳烃。 5.2 该方法可用于测定孔隙水中每升纳米至毫克的多环芳烃浓度。SPME萃取需要少量孔隙水，每次测定仅需1.5 mL，几乎不会产生溶剂萃取废物。

1.1 The U.S. Environmental Protection Agency (USEPA) narcosis model for benthic organisms in sediments contaminated with polycyclic aromatic hydrocarbons (PAHs) is based on the concentrations of dissolved PAHs in the interstitial water or “pore water” in sediment. This test method covers the separation of pore water from PAH-impacted sediment samples, the removal of colloids, and the subsequent measurement of dissolved concentrations of the required 10 parent PAHs and 14 groups of alkylated daughter PAHs in the pore water samples. The “24 PAHs” are determined using solid-phase microextraction (SPME) followed by Gas Chromatography/Mass Spectrometry (GC/MS) analysis in selected ion monitoring (SIM) mode. Isotopically labeled analogs of the target compounds are introduced prior to the extraction, and are used as quantification references. 1.2 Lower molecular weight PAHs are more water soluble than higher molecular weight PAHs. Therefore, USEPA-regulated PAH concentrations in pore water samples vary widely due to differing saturation water solubilities that range from 0.2 µg/L for indeno[1,2,3-cd]pyrene to 31 000 µg/L for naphthalene. This method can accommodate the measurement of microgram per litre concentrations for low molecular weight PAHs and nanogram per litre concentrations for high molecular weight PAHs. 1.3 The USEPA narcosis model predicts toxicity to benthic organisms if the sum of the toxic units (ΣTU c ) calculated for all “34 PAHs” measured in a pore water sample is greater than or equal to 1. For this reason, the performance limit required for the individual PAH measurements was defined as the concentration of an individual PAH that would yield 1 / 34 of a toxic unit (TU). However, the focus of this method is the 10 parent PAHs and 14 groups of alkylated PAHs ( Table 1 ) that contribute 95 % of the toxic units based on the analysis of 120 background and impacted sediment pore water samples. 3 The primary reasons for eliminating the rest of the 5-6 ring parent PAHs are: (1) these PAHs contribute insignificantly to the pore water TU, and (2) these PAHs exhibit extremely low saturation solubilities that will make the detection of these compounds difficult in pore water. This method can achieve the required detection limits, which range from approximately 0.01 µg/L, for high molecular weight PAHs, to approximately 3 µg/L for low molecular weight PAHs. 1.4 The test method may also be applied to the determination of additional PAH compounds (for example, 5- and 6-ring PAHs as described in Hawthorne et al.). 4 However, it is the responsibility of the user of this standard to establish the validity of the test method for the determination of PAHs other than those referenced in 1.1 and Table 1 . 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, refer to Section 9 . 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This method directly determines the concentrations of dissolved PAH concentrations in environmental sediment pore water samples. The method is important from an environmental regulatory perspective because it can achieve the analytical sensitivities to meet the goals of the USEPA narcosis model for protecting benthic organisms in PAH contaminated sediments. Regulatory methods using solvent extraction have not achieved the wide calibration ranges from nanograms to milligrams per litre and the required levels of detection in the nanogram-per-litre range. In addition, conventional solvent extraction methods require large aliquot volumes (litre or larger), use of large volumes of organic solvents, and filtration to generate the pore water. This approach entails the storage and processing of large volumes of sediment samples and loss of low molecular weight PAHs in the filtration and solvent evaporation steps. 5.2 This method can be used to determine nanogram to milligram per litre PAH concentrations in pore water. Small volumes of pore water are required for SPME extraction, only 1.5 mL per determination and virtually no solvent extraction waste is generated.