Nontarget Analysis and Characterization of a Group of Abundant Polyfluoroalkyl Substances─Fluorinated Benzoylurea Pesticides and Their Analogues and Transformation Products in Fish by LC-HRMS and Chemical Species-Specific Algorithms

Poly- and perfluoroalkyl substances (PFASs) are a large class of fluorinated chemicals used in various industrial and agrochemical products such as fluorinated benzoylurea (FBU) pesticides. Initiated from an incidental and preliminary finding of three high-abundance FBUs in fish, this study implemented nontarget analysis and characterization for FBUs together with their analogues and transformation products (TPs) in fish using liquid chromatography, high-resolution mass spectrometry, and chemical species-specific algorithms. A total of 23 FBU-relevant compounds were found and tentatively/accurately elucidated with structures, including 18 PFASs and 5 non-PFAS compounds, of which 4 were original FBUs, 8 were FBU analogues, and 11 were FBU-TPs. The total concentrations of FBU-relevant compounds were 0.8-1919.3 ng/g in the fish samples. The analysis strategy and data-processing algorithms can be extended to other fluorine-containing pesticides, and the characterization results provide a new understanding of PFAS pollution and unveil an important source of PFAS pollutants, the agrochemical utilization of FBUs.