Heavy metal complexation in polluted molluscs. III. Periwinkles (Littorina littorea), cockles (Cardium edule) and scallops (Chlamys opercularis).

The accumulation of cadmium, zinc and copper by environmentally contaminated periwinkles, cockles and scallops has been studied by gel permeation chromatography of water-soluble extracts of the shellfish. Three distinct low mol. wt. (less than 3000) zinc complexes were separated from periwinkle extracts. Copper and cadmium were present as a single low mol. wt. species which is apparently responsible for the elevated copper levels in Littorina littorea.