Variation in arsenolipid concentrations in seafood consumed in Japan

Variation in arsenolipid concentrations was assessed in 18 seafood samples including fish, shellfish, and crustaceans purchased in Japan. Analyses were performed by high performance liquid chromatography-inductively coupled plasma mass spectrometry/electrospray ionization tandem mass spectrometry. Stable isotope ratios for nitrogen and carbon were also measured in the samples for obtaining trophic level information of the species. Arsenic-containing hydrocarbons (AsHCs) and arsenic-containing fatty acids (AsFAs) were detected in the seafood samples; the toxic AsHCs were found in all of the seafood samples with large variation in the concentrations (83 ± 73 ng As/g fw, coefficient of variation = 88%). Our previous point estimate of health risk of AsHCs intake via seafood consumption in Japan, based on average AsHC concentration in seafood, suggested insignificant risk, and the present study supports our previous estimate. AsHC concentrations significantly correlated with lipid content of the seafood samples (r = 0.67, p < 0.01), a result expected because of the fat solubility of the compounds. The AsHCs concentrations, however, were not significantly correlated with nitrogen stable isotope ratios suggesting that AsHCs do not biomagnify. The source of the observed large variation in AsHC concentrations will be the subject of further investigation.