Determination of arsenic species in edible periwinkles (Littorina littorea) by HPLC–ICPMS and XAS along a contamination gradient

•Examine arsenic species in Littorina littorea along an As concentration gradient.•Total As concentrations in the periwinkle tissues ranged from 56 to 840 mg · kg− 1 dry wt.•Inorganic As was positively correlated with total As (reached 600 mg · kg− 1 dry wt).•High inorganic As within L. littorea poses a toxicological risk to consumers.

Arsenic is naturally found in the tissues of marine animals, usually as the non-toxic arsenical arsenobetaine, but exposure to elevated arsenic concentrations in the environment may alter the arsenic species distribution within tissues of the organism. This study examined the arsenic species in the tissues of the marine periwinkle (Littorina littorea) along an arsenic concentration gradient in the sediment. The arsenicals in L. littorea were examined using the complementary analytical methods high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC–ICPMS) and X-ray absorption spectroscopy (XAS). Total arsenic concentrations in the periwinkle tissues ranged from 56 to 840 mg · kg− 1 dry weight (equivalent to 13 to 190 mg · kg− 1 wet weight). Inorganic arsenicals were found to be positively correlated with total arsenic concentrations (R2 = 0.993) and reached 600 mg · kg− 1 dry weight, the highest reported to date in marine organisms. These high inorganic arsenic concentrations within this low trophic organism pose a potential toxicological risk to higher trophic consumers.