U.S. Environmental Protection Agency, Atlantic Ecology Division, Narragansett, Rhode Island 02882, USA.
Environ Sci Technol. 2012 Nov 6;46(21):11937-47. doi: 10.1021/es302139y. Epub 2012 Oct 26.
Passive sampling was used to deduce water concentrations of persistent organic pollutants (POPs) in the vicinity of a marine Superfund site on the Palos Verdes Shelf, California, USA. Precalibrated solid phase microextraction (SPME) fibers and polyethylene (PE) strips that were preloaded with performance reference compounds (PRCs) were codeployed for 32 d along an 11-station gradient at bottom, surface, and midwater depths. Retrieved samplers were analyzed for DDT congeners and their breakdown products (DDE, DDD, DDMU, and DDNU) and 43 PCB congeners using GC-EI- and NCI-MS. PRCs were used to calculate compound-specific fractional equilibration achieved in situ for the PE samplers, using both an exponential approach to equilibrium (EAE) and numerical integration of Fickian diffusion (NI) models. The highest observed concentrations were for p,p'-DDE, with 2200 and 990 pg/L deduced from PE and SPME, respectively. The difference in these estimates could be largely attributed to uncertainty in equilibrium partition coefficients, unaccounted for disequilibrium between samplers and water, or different time scales over which the samplers average. The concordance between PE and SPME estimated concentrations for DDE was high (R(2) = 0.95). PCBs were only detected in PE samplers, due to their much larger size. Near-bottom waters adjacent to and down current from sediments with the highest bulk concentrations exhibited aqueous concentrations of DDTs and PCBs that exceeded Ambient Water Quality Criteria (AWQC) for human and aquatic health, indicating the need for future monitoring to determine the effectiveness of remedial activities taken to reduce adverse effects of contaminated surface sediments.
被动采样法被用于推断美国加利福尼亚州帕洛斯弗迪斯架海洋超级基金场址附近水域中持久性有机污染物（POPs）的浓度。经预校准的固相微萃取（SPME）纤维和预先加载有性能参照化合物（PRC）的聚乙烯（PE）条带在底层、表层和中层沿 11 站梯度共部署 32 天。回收的采样器使用 GC-EI- 和 NCI-MS 对滴滴涕同系物及其分解产物（DDE、DDD、DDMU 和 DDNU）和 43 种多氯联苯同系物进行了分析。使用指数平衡法（EAE）和菲克扩散的数值积分（NI）模型，将 PRC 用于计算 PE 采样器在现场实现的化合物特异性平衡分数，以获得平衡分数。观察到的最高浓度是对，对 -DDE，PE 和 SPME 分别推导出 2200 和 990pg/L。这些估计值的差异可能主要归因于平衡分配系数的不确定性、采样器与水之间未考虑的不平衡，或采样器平均的不同时间尺度。DDE 的 PE 和 SPME 估算浓度之间具有高度一致性（R(2) = 0.95）。由于其尺寸较大，仅在 PE 采样器中检测到多氯联苯。与沉积物相邻的底层和下游水流附近的水域中，滴滴涕和多氯联苯的浓度超过了人类和水生健康的环境水质标准（AWQC），这表明需要进行未来的监测，以确定为减少受污染表层沉积物的不利影响而采取的补救措施的有效性。
