Combination of extractive techniques followed by HPLC-MS/MS analysis to monitor ent-agathic acid in fish treated with Copaifera duckei Dwyer

Plants are used as therapeutic alternatives in Veterinary Medicine, including therapies for food-producing ani-mals. However, these medicinal resources can sometimes contain dangerous substances, and when used in an-imals that supply food, they stand out from the point of view of food safety. The diterpene ent-agathic acid, a component of Copaifera duckei oleoresin, is an example of substances already described with toxic activity in mammals. Thus, this study aimed to propose combining two extractive techniques followed by high-performance liquid chromatography coupled mass spectrometry analysis to monitor residues of ent-agathic acid in Piaractus mesopotamicus fillet treated in an immersion bath with Copaifera duckei oleoresin. An optimized combination of solid-liquid extraction (using acidified acetonitrile) and dispersive liquid-liquid microextraction (using acidified water and chloroform as dispersive and extracting solvent, respectively) was performed to recover the target analyte, added to the development of HPLC-MS/MS method with adequate validation parameters to quantify the ent-agathic acid present in the fish fillet. In vivo tests of residual persistence of ent-agathic acid in fishes treated with C. duckei oleoresin were performed, indicating the non-detection of the target diterpene (< 6.1 & mu;g/mL). The combined extractive procedure followed by quantitative analysis in the in vivo test of residual persistence of the target analyte in fish indicated the absence of ent-agathic acid in all samples. Thus, the data found might contribute to understanding the use of oleoresins from C. duckei as an alternative to traditional veterinary products.