Arsenic concentrations and speciation in the tissues of ringed seals (Phoca hispida) from Pangnirtung, Canada

Concentrations of total arsenic and arsenic compounds were determined in tissues of ringed seals (Phoca hispida) using hydride generation-atomic absorption spectrometry and high-performance liquid chromatography-inductively coupled plasma mass spectrometry. Arsenic was accumulated at high concentrations in the blubber as lipid-soluble arsenic compounds (arsenolipids). Arsenobetaine (AB) was the most predominant arsenical in the liver, kidney, muscle and gonad, accounting for about 70% of total arsenic in these tissues. Significant positive correlations were observed for AB concentrations among liver, kidney, muscle and gonad, suggesting that the distribution of AB among these tissues was at equilibrium. Concentrations of AB in the tissues were elevated up to 1-3 years of age, and then fell to a lower level. In contrast, dimethylarsinic acid concentration was significantly increased with age in the liver and kidney. Arsenocholine was also detected in the liver, kidney and gonad, but was not detected in the muscle. Among the arsenic compounds, only AB showed a considerable decrease of the concentration in the gastrointestinal contents with their passing through the gastrointestinal tract, which might indicate that the absorption rate of AB was higher than the absorption rates of other arsenic compounds in ringed seals. To our knowledge, this is the first report of arsenic speciation in several tissues and gastrointestinal contents in marine mammals. Copyright (C) 2002 John Wiley Sons, Ltd.