Nontarget screening analysis of organic compounds in river sediments: a case study in the Taipu River of the Yangtze River Delta Region in China

Sediments are the vital fate of organic compounds, and the recognition of organic compounds in sediments is constructive in providing comprehensive and long-term information. In this study, a three-step nontarget screening (NTS) analysis workflow using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOFMS) revealed the extensive existence of organic compounds in the Taipu River sediment. Organic compounds (705) were detected and divided into four structure-related groups or eight use-related classes. In the Taipu River’s mainstream, a significant difference was found in the composition profiles of the identified organic compounds among various sites, demonstrating the organic compounds were more abundant in the midstream and downstream than in the upstream. Meanwhile, the hydrodynamic force was recognized as a potential factor influencing organic compounds’ occurrence. Based on multiple statistical analyses, the shipping and textile printing industries were considered the significant contributors to the identified organic compounds. Considering the principles of the priority substances and the current status of the substances, two traditional pollutants and ten emerging organic compounds were recognized as the priority organic compounds for the Taipu River. Conclusively, this study established a workflow for NTS analysis of sediment samples and demonstrated the necessity of NTS analysis to evaluate the impact of terrestrial emissions of organic compounds on the aquatic environment.