Optimization and validation of a micro-QuEChERS method coupled with LC-MS for the analysis of pesticides in fish tissue.

Pesticides have been widely used worldwide; some persist in the environment for long periods. These compounds may reach non-target locations, such as rivers and streams, after their application and may contaminate organisms that live there. As a result, aquatic organisms are excellent indicators of environmental contamination and predictors of the fate of the compounds. In addition, carnivorous fish become part of contaminant biomagnification processes since they transfer high concentrations of pesticide residues to humans. Therefore, this study aimed to optimize and validate a method to determine 24 pesticides (8 fungicides, 6 insecticides, and 10 herbicides) in fish muscle with the use of a micro-QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method coupled with liquid chromatography-mass spectrometry (LC-MS). The optimized method showed good linearity (r2 > 0.99), precision (RSD < 20%), and limits of quantification (LOQ) which ranged from 2 to 40 µg∙kg-1 and accuracy that ranged between 70 and 120% in the cases of all compounds. Thus, the micro-QuEChERS method proposed for the determination of pesticides in fish muscle with the use of LC-MS proved to be effective and may be applied to routine monitoring and analysis work.