DEVELOPMENT AND VALIDATION OF A METHOD TO DETERMINE PESTICIDE RESIDUES IN OWL BLOOD

Owls are birds at the top of the food chain and play an important role in population control of their prey, in the quality of the environment, and as a bioindicator species. Studying the accumulation of xenobiotics and their effects in these animals is crucial because predators can accumulate and biomagnify chemical substances. In Brazil, studies on the presence and effects of pesticide residues on owls are scarce. Therefore, we developed and validated a method for the analysis of four pesticides in the blood. We used liquid chromatography coupled with tandem mass spectrometry because of its high sensitivity and specificity. The compounds tested were Abamectin, Atrazine, Chlorpyrifos-ethyl, and Diuron, all of which are widely used in Brazil. Biomarkers of effects (cholinesterase and micronuclei) were also evaluated. We analyzed 16 owls from the north of the State of Rio Grande do Sul (Brazil). The validated method was suitable for pesticide analysis and will serve as a routine follow-up for acute poisonings. Although pesticides are widely used, we found no evidence that owls were affected by the tested pesticides.