Monitoring polycyclic aromatic hydrocarbon contamination in avian blood: development of a quick analytical HPLC approach and pilot application to Brown boobies (Sula leucogaster) in Southeastern Brazil

Polycyclic aromatic hydrocarbons (PAHs) are toxic, carcinogenic organic contaminants widely distributed throughout the marine environment, directly affecting marine life and human health. Surveying these compounds in sentinel organisms, such as seabirds, is an effective way to assess environmental quality. In this sense, this research aimed to (i) develop and validate a high-performance liquid chromatography (HPLC) analytical method for the quantification of the 16 priority PAHs in blood plasma; (ii) establish an easy and quick protocol to reduce sample handling and potential contamination; and (iii) apply the method to Brown booby ( Sula leucogaster ) blood samples from specimens collected along the coast of the state of Rio de Janeiro in 2025. The performance parameters of the developed method met well-established criteria and the Limits of Quantification (LOQ) achieved herein (0.06 - 4.48 ng mL -1 ) are consistent with the main goal and comparable to recent literature. The analyzed samples (n=13) presented low PAH concentrations (from -1 ), consistent with chronic background exposure and no evidence of acute events. The contamination profile suggests exposure to low molecular weight PAH, possibly due to Brown booby trophic position and habitat. This research delivers an initial database of an ongoing monitoring project for future assistance in the event of oil spills or other acute contamination sources.