Study of bioconcentration of oxybenzone in gilt-head bream and characterization of its by-products

The widespread occurrence of UV filters such as oxybenzone (OXY) in the aquatic ecosystems has raised social and scientific concern due to their high bioaccumulation potential and possible adverse effects in organisms. Within this context, the aim of the present work was to study the uptake, distribution, metabolization and elimination of OXY in different tissues (liver, gill and muscle) and biofluids (bile and plasma) of gilt-head bream (Sparus aurata) in a controlled seawater ecosystem (50 ng/mL OXY) within a 14-day exposure. The highest OXY concentrations in all the tissue/biofluids were found at the end of the experiment. The highest OXY levels were found in bile (1.8-17 mu g/mL). In the case of liver, the concentrations found (9-160 ng/g) were lower than those expected for a lipidic matrix, which could be explained by a high OXY metabolization. Up to 20 Phase I and Phase II by-products of OXY were annotated by means of liquid chromatography-high resolution mass spectrometry, of which 12 were reported for the first time. In addition to OXY, its by-products might also cause adverse effects and their biomonitoring is advisable in order to fully characterize OXY exposure. (C) 2018 Elsevier Ltd. All rights reserved.