Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China.
Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China; Southern California Coastal Water Research Project Authority, Costa Mesa, CA, 92626, USA.
Chemosphere. 2020 Aug;252:126534. doi: 10.1016/j.chemosphere.2020.126534. Epub 2020 Mar 20.
Passive sampling techniques have been widely used to determine the dissolved concentration profiles of hydrophobic organic compounds (HOCs) in sediment porewater. However, the effects of having a protection for the passive sampler on profiling HOCs concentrations in sediment porewater, especially in deep sediment, have remained unclear. To address this issue, low density polyethylene passive samplers with and without protectors, which consisted of glass fiber filter and porous stainless steel shield, were simultaneously deployed in sediment of the Dongjiang River, South China. The results showed that the protectors retarded the dissipation of performance reference compounds (PRCs) from the sampler by a factor of 2-9. The protectors seemed to exert a negligible effect on the measured concentrations of PAHs, BDE-47, and BDE-99 in surficial sediment porewater (0-14 cm depth) from both samplers. However, the sediment porewater concentration profiles of PAHs and BDE-47 from the sampler with protectors were in agreement with those normalized by dry weight in deep sediment (16-34 cm depth), indicating that a diffusion layer established by the protectors may minimize the probability of local depletion of the target analytes in deep sediment. In addition, the log K values of PAHs, BDE-47, and BDE-99 exhibited a slight increasing trend with sediment depth. This finding suggested that in situ passive sampling techniques could be a feasible tool in determining the site-specific log K values of HOCs at different sediment depths.
被动采样技术已广泛用于测定沉积物孔隙水中疏水性有机化合物（HOCs）的溶解浓度分布。然而，保护被动采样器对沉积物孔隙水中 HOCs 浓度分布的影响，尤其是在深沉积物中，仍不清楚。为了解决这个问题，同时在华南东江的沉积物中部署了带有和不带有保护套的低密度聚乙烯被动采样器，保护套由玻璃纤维过滤器和多孔不锈钢护套组成。结果表明，保护套将性能参考化合物（PRCs）从采样器中的耗散速度减缓了 2-9 倍。保护套似乎对两种采样器中表层沉积物孔隙水中（0-14cm 深度）的 PAHs、BDE-47 和 BDE-99 的测量浓度没有影响。然而，带有保护套的采样器中 PAHs 和 BDE-47 的沉积物孔隙水浓度分布与通过干重归一化的深沉积物（16-34cm 深度）中的浓度分布一致，这表明保护套建立的扩散层可能最小化了目标分析物在深沉积物中局部耗尽的可能性。此外，PAHs、BDE-47 和 BDE-99 的 log K 值随沉积物深度呈略有增加的趋势。这一发现表明，原位被动采样技术可能是一种可行的工具，可用于确定不同沉积物深度下 HOCs 的特定地点 log K 值。
