Evaluation of Acephate Metabolites Generated by Zebrafish (Danio rerio) Using LC-HRMS and Metabolomics Approach

Acephate is an organophosphate insecticide widely used. This pesticide can be metabolized into methamidophos, a molecule highly toxic. Both have demonstrated the ability to promote serious toxic effects on nontarget organisms and have been identified in surface waters around the world. Therefore, it is important to understand their behavior in the environment and in living organisms. Zebrafish are considered an excellent animal model for studying the toxicity of xenobiotics present in water. This work aimed to identify acephate metabolites formed in zebrafish and excreted into tank water using liquid chromatography coupled to a high-resolution spectrometer (LC-HRMS) to obtain biomarkers of exposure in aquatic environments. For this purpose, three groups were established: treatment, negative, and stability. After exposure, water samples from the tanks were collected for analysis by LC-HRMS. The experiments allowed the putative identification of three acephate metabolites that can be used to monitor exposure to this pesticide with a high degree of confidence. The approach used to identify these exposure markers shows promise since water is a cleaner and easier-to-obtain matrix when compared to biological matrices. To the best of our knowledge, this is the first study on the identification of acephate metabolites in zebrafish.