Occurrence of several arsenic compounds in the liver of birds, cetaceans, pinnipeds, and sea turtles

Concentrations of total arsenic and individual arsenic compounds were determined in livers of birds, cetaceans, pinnipeds, and sea turtles by using hydride generation‐atomic absorption spectrometry and high‐performance liquid chromatography/inductively coupled plasma‐mass spectrometry. Hepatic arsenic concentrations in loggerhead turtles (11.2 ± 3.0 μg/g dry wt) and black‐footed albatrosses (12.2 ± 10.8 μg/g dry wt) were extremely high among the species examined, and the values were comparable with those of lower trophic marine animals such as fishes, cephalopods, crustaceans, and shellfishes. In all the species, arsenobetaine was the predominant arsenic compound in the livers. Especially, for black‐footed albatrosses and black‐tailed gull, the mean percentage of arsenobetaine was as high as 97.1 and 87.5, respectively, of extractable arsenic. The present study is among the first on arsenic speciation in avian species. Total arsenic concentration was strongly correlated with the concentration of arsenobetaine, while no significant relationship was observed between total arsenic concentration and other arsenic compounds in these animals. Because arsenobetaine is known to be rapidly excreted into the urine in humans and experimental animals, the observed results suggest that higher trophic marine animals might have a unique metabolism of arsenobetaine and that arsenobetaine plays an important role in the accumulation of arsenic in these animals.