Institute for Biodiversity and Ecosystem Dynamics , University of Amsterdam , Science Park 904 , 1098 XH Amsterdam , The Netherlands.
Eawag, Swiss Federal Institute of Aquatic Science and Technology , Überlandstrasse 133 , 8600 Dübendorf , Switzerland.
Environ Sci Technol. 2019 Jul 2;53(13):7584-7594. doi: 10.1021/acs.est.9b01750. Epub 2019 Jun 18.
The historic emissions of polar micropollutants in a natural drinking water source were investigated by nontarget screening with high-resolution mass spectrometry and open cheminformatics tools. The study area consisted of a riverbank filtration transect fed by the river Lek, a branch of the lower Rhine, and exhibiting up to 60-year travel time. More than 18,000 profiles were detected. Hierarchical clustering revealed that 43% of the 15 most populated clusters were characterized by intensity trends with maxima in the 1990s, reflecting intensified human activities, wastewater treatment plant upgrades and regulation in the Rhine riparian countries. Tentative structure annotation was performed using automated in silico fragmentation. Candidate structures retrieved from ChemSpider were scored based on the fit of the in silico fragments to the experimental tandem mass spectra, similarity to openly accessible accurate mass spectra, associated metadata, and presence in a suspect list. Sixty-seven unique structures (72 over both ionization modes) were tentatively identified, 25 of which were confirmed and included contaminants so far unknown to occur in bank filtrate or in natural waters at all, such as tetramethylsulfamide. This study demonstrates that many classes of hydrophilic organics enter riverbank filtration systems, persisting and migrating for decades if biogeochemical conditions are stable.
本研究采用高分辨质谱非靶向筛查和开放化学信息学工具，调查了天然饮用水源中极地微污染物的历史性排放情况。研究区域由 Lek 河河岸过滤剖面组成，该河是莱茵河下游的一条支流，其水流具有长达 60 年的滞留时间。研究共检测到 18000 多个谱图。层次聚类分析表明，15 个最常见的聚类中有 43%的聚类特征是强度趋势呈 20 世纪 90 年代的最大值，这反映了人类活动的加剧、废水处理厂的升级以及莱茵河流域国家的监管。使用自动计算的片段化方法进行了初步结构注释。根据计算得到的碎片与实验串联质谱的吻合度、与公开可得的精确质量谱的相似性、相关元数据以及是否在可疑列表中的得分，从 ChemSpider 中检索候选结构。共暂定鉴定出 67 种独特结构（两种离子模式下共 72 种），其中 25 种结构得到确认，包括迄今为止在河岸过滤物或天然水中均未知存在的污染物，如四甲基磺酰胺。本研究表明，如果生物地球化学条件稳定，许多亲水性有机物会进入河岸过滤系统，并在数十年内持续存在和迁移。
