Kiefer Karin, Du Letian, Singer Heinz, Hollender Juliane
Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092 Zurich, Switzerland.
Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.
Water Res. 2021 May 15;196:116994. doi: 10.1016/j.watres.2021.116994. Epub 2021 Mar 2.
Groundwater is a major drinking water resource but its quality with regard to organic micropollutants (MPs) is insufficiently assessed. Therefore, we aimed to investigate Swiss groundwater more comprehensively using liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). First, samples from 60 sites were classified as having high or low urban or agricultural influence based on 498 target compounds associated with either urban or agricultural sources. Second, all LC-HRMS signals were related to their potential origin (urban, urban and agricultural, agricultural, or not classifiable) based on their occurrence and intensity in the classified samples. A considerable fraction of estimated concentrations associated with urban and/or agricultural sources could not be explained by the 139 detected targets. The most intense nontarget signals were automatically annotated with structure proposals using MetFrag and SIRIUS4/CSI:FingerID with a list of >988,000 compounds. Additionally, suspect screening was performed for 1162 compounds with predicted high groundwater mobility from primarily urban sources. Finally, 12 nontargets and 11 suspects were identified unequivocally (Level 1), while 17 further compounds were tentatively identified (Level 2a/3). amongst these were 13 pollutants thus far not reported in groundwater, such as: the industrial chemicals 2,5-dichlorobenzenesulfonic acid (19 detections, up to 100 ng L), phenylphosponic acid (10 detections, up to 50 ng L), triisopropanolamine borate (2 detections, up to 40 ng L), O-des[2-aminoethyl]-O-carboxymethyl dehydroamlodipine, a transformation product (TP) of the blood pressure regulator amlodipine (17 detections), and the TP SYN542490 of the herbicide metolachlor (Level 3, 33 detections, estimated concentrations up to 100-500 ng L). One monitoring site was far more contaminated than other sites based on estimated total concentrations of potential MPs, which was supported by the elucidation of site-specific nontarget signals such as the carcinogen chlorendic acid, and various naphthalenedisulfonic acids. Many compounds remained unknown, but overall, source related prioritisation proved an effective approach to support identification of compounds in groundwater.
地下水是主要的饮用水资源，但其有机微污染物（MPs）的质量评估尚不充分。因此，我们旨在利用液相色谱高分辨率串联质谱（LC-HRMS/MS）更全面地研究瑞士地下水。首先，根据与城市或农业源相关的498种目标化合物，将来自60个地点的样本分类为受城市或农业影响程度高或低。其次，根据所有LC-HRMS信号在分类样本中的出现情况和强度，将其与潜在来源（城市、城市和农业、农业或无法分类）相关联。与城市和/或农业源相关的估计浓度中有相当一部分无法用检测到的139种目标物来解释。使用MetFrag和SIRIUS4/CSI:FingerID以及超过988,000种化合物的列表，对强度最高的非目标信号自动进行结构推测注释。此外，对主要来自城市源的1162种预测在地下水中具有高迁移率的化合物进行了可疑物筛查。最后，明确鉴定出12种非目标物和11种可疑物（1级），另外还初步鉴定出17种化合物（2a/3级）。其中有13种污染物此前未在地下水中报道，例如：工业化学品2,5-二氯苯磺酸（19次检测，最高100 ng/L）、苯膦酸（10次检测，最高50 ng/L）、硼酸三异丙醇胺（2次检测，最高40 ng/L）、降压药氨氯地平的转化产物O-去[2-氨基乙基]-O-羧甲基氨氯地平（17次检测）以及除草剂异丙甲草胺的转化产物SYN542490（3级，33次检测，估计浓度最高100 - 500 ng/L）。根据潜在微污染物的估计总浓度，有一个监测点的污染程度远高于其他地点，这一点得到了特定地点非目标信号（如致癌物质氯菌酸和各种萘二磺酸）的阐明的支持。许多化合物仍未知，但总体而言，基于来源的优先排序证明是支持鉴定地下水中化合物的有效方法。
