Department of Applied Environmental Science (ITM), Stockholm University, Svante Arrhenius väg 8, SE-106 91 Stockholm, Sweden.
Environ Sci Process Impacts. 2014 Mar;16(3):464-72. doi: 10.1039/c3em00589e. Epub 2014 Jan 21.
Passive equilibrium samplers deployed in two or more media of a system and allowed to come to equilibrium can be viewed as 'chemometers' that reflect the difference in chemical activities of contaminants between the media. We applied silicone-based equilibrium samplers to measure relative chemical activities of seven 'indicator' polychlorinated biphenyls (PCBs) and hexachlorobenzene in eels and sediments from a Swedish lake. Chemical concentrations in eels and sediments were also measured using exhaustive extraction methods. Lipid-normalized concentrations in eels were higher than organic carbon-normalized concentrations in sediments, with biota-sediment accumulation factors (BSAFs) of five PCBs ranging from 2.7 to 12.7. In contrast, chemical activities of the same pollutants inferred by passive sampling were 3.5 to 31.3 times lower in eels than in sediments. The apparent contradiction between BSAFs and activity ratios is consistent with the sorptive capacity of lipids exceeding that of sediment organic carbon from this ecosystem by up to 50-fold. Factors that may contribute to the elevated activity in sediments are discussed, including slower response of sediments than water to reduced emissions, sediment diagenesis and sorption to phytoplankton. The 'chemometer' approach has the potential to become a powerful tool to study the thermodynamic controls on persistent organic chemicals in the environment and should be extended to other environmental compartments.
被动平衡采样器部署在系统的两种或多种介质中，并允许达到平衡，可以被视为“化学计量器”，反映了介质之间污染物化学活度的差异。我们应用基于硅的平衡采样器来测量瑞典湖中鳗鱼和沉积物中七种“指示”多氯联苯 (PCB) 和六氯苯的相对化学活度。还使用彻底提取方法测量了鳗鱼和沉积物中的化学浓度。鳗鱼中的脂类归一化浓度高于沉积物中的有机碳归一化浓度，五种 PCB 的生物 - 沉积物积累因子 (BSAF) 范围为 2.7 至 12.7。相比之下，通过被动采样推断出的相同污染物的化学活度在鳗鱼中比在沉积物中低 3.5 至 31.3 倍。BSAF 和活性比之间的明显矛盾与该生态系统中脂类的吸附能力比沉积物有机碳高出 50 倍一致。讨论了可能导致沉积物中活性升高的因素，包括沉积物对减少排放的响应速度比水慢、沉积物成岩作用以及对浮游植物的吸附。“化学计量器”方法有可能成为研究环境中持久性有机化学品热力学控制的有力工具，应将其扩展到其他环境隔室。
