Groundwater is a major drinking water resource, but its quality is threatened by a broad variety of anthropogenic micropollutants (MPs), originating from agriculture, industry, or households, and undergoing various transformation processes during subsurface passage. To determine a worst-case impact of pesticide application in agriculture on groundwater quality, a target and suspect screening for more than 300 pesticides and more than 1100 pesticide transformation products (TPs) was performed in 31 Swiss groundwater samples which predominantly originated from areas with intensive agriculture. To assess additional urban contamination sources, more than 250 common urban MPs were quantified. Most of the screened pesticide TPs were experimentally observed by the pesticide producers within the European pesticide registration. To cover very polar pesticide TPs, vacuum-assisted evaporative concentration was used for enrichment, followed by liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). Based on intensity, isotope pattern, retention time, and in silico fragmentation, the suspect hits were prioritised and verified. We identified 22 suspects unequivocally and five tentatively; 13 TPs are reported here for the first time to be detected in groundwater. In 13 out of 31 groundwater samples, the total concentration of the 20 identified and quantified suspects (1 pesticide and 19 pesticide TPs) exceeded the total concentration of the 519 targets (236 pesticides and TPs; 283 urban MPs) for which we screened. Pesticide TPs had higher concentrations than the parent pesticides, illustrating their importance for groundwater quality. The newly identified very polar chlorothalonil TP R471811 was the only compound detected in all samples with concentrations ranging from 3 to 2700 ng/L. Agricultural MP concentration and detection frequency correlated with agricultural land use in the catchment, except for aquifers, where protective top layers reduced MP transport from the surface. In contrast to agricultural MPs, urban MPs displayed almost no correlation with land use. The dominating entry pathway of urban MPs was river bank filtration.

地下水是一种主要的饮用水资源，但是其质量受到来自农业，工业或家庭的各种人为微量污染物（MPs）的威胁，并且在地下通道中经历各种转化过程。为了确定农药在农业中的应用对地下水质量的最坏情况，我们对31种瑞士地下水样品进行了目标和可疑筛查，其中有300多种农药和1100多种农药转化产品（TPs），这些样品主要来自密集地区农业。为了评估其他城市污染源，量化了250多个普通城市议员。在欧洲农药注册中，大多数筛选的农药TP都是由农药生产商通过实验观察到的。为了覆盖极极性农药的TP，使用了真空辅助蒸发浓缩法进行了浓缩，然后进行了液相色谱高分辨率串联质谱（LC-HRMS / MS）。根据强度，同位素模式，保留时间和计算机碎片，对可疑命中点进行优先级排序和验证。我们明确确定了22名嫌疑犯，暂定确定了5名嫌疑犯。此处首次报告了13种TP，它们是在地下水中首次检测到的。在31个地下水样本中的13个中，已识别和量化的20个嫌疑人（1个农药和19个农药TPs）的总浓度超过了我们筛选的519个目标（236个农药和TPs； 283个城市MPs）的总浓度。农药TP的浓度高于母体农药，说明了其对地下水质量的重要性。新鉴定的极极性百菌清TP R471811是所有样品中唯一检测到的浓度为3至2700 ng / L的化合物。除蓄水层外，农业MP浓度和检测频率与流域内农业土地使用有关，在含水层中，保护性顶层减少了MP从地面的运输。与农业国会议员相比，城市国会议员与土地用途几乎没有相关性。城市国会议员的主要进入途径是河岸过滤。与农业国会议员相比，城市国会议员与土地用途几乎没有相关性。城市议员的主要进入途径是河岸过滤。与农业国会议员相比，城市国会议员与土地用途几乎没有相关性。城市国会议员的主要进入途径是河岸过滤。