Howard A G, Nickless G
Chem Biol Interact. 1978 Nov;23(2):227-31. doi: 10.1016/0009-2797(78)90008-x.
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.