Determination of benzoylurea pesticides in fish by liquid chromatography-high resolution mass spectrometry and assessment of their embryotoxicity in zebrafish.

Benzoylureas are an important class of insecticides widely used in agriculture and aquaculture owing to their high efficacy and specific mode of action in pest control. Due to their environmental persistence and potential ecological toxicity, benzoylureas have raised growing scientific and public concern. In this study, a reliable and sensitive method was developed and validated for determination of 8 benzoylurea insecticides in fish. The fish samples underwent ultrasonic-assisted extraction with acetonitrile/methanol, followed by purification via gel permeation chromatography. The instrumental analysis was implemented by liquid chromatography high-resolution mass spectrometry, with electrospray ionization operated in negative mode. The accuracies were 87.2-119.4%, with relative standard deviations (RSDs) less than 14.2%. Satisfactory recoveries were obtained for all the analytes, within the range of 62.1-98.1% (RSDs ≤ 15.0%), and the limits of quantification were 5.0 ng g-1. The method was successfully applied to preliminary investigation of benzoylurea residues in edible fish. The findings revealed that the fish samples from several regions were heavily contaminated with benzoylureas, and all the investigated benzoylureas were detectable in the fish. Notably, hexaflumuron and chlorfluazuron were found in all the fish samples. Complementary zebrafish embryotoxicity assays of fluazuron and lufenuron showed hatching delays at concentrations ≥1.0 mg L-1. The analytical method presents a practical approach for analyzing benzoylureas in fish, and provides foundational data for future research on food safety monitoring and environmental risk assessment. The results of this study underlined the hazards of benzoylureas to aquatic organisms and the eco-environment, highlighting the necessity for further research.