Determination and Distribution of Trace Elements in Marine Invertebrates

Abstract

Inductively coupled plasma atomic fluorescence spectrometry (ICP-AFS) was applied to the determination of trace elements in edible parts of marine invertebrates. Element contents (except aluminium and lead) in the NBS standard reference material 1566: oyster tissue measured by ICP-AFS were in agreement with certified values. Furthermore, analytical results indicated that ICP-AFS is one of the effective multielement analyses, because of a simultaneous determination capability, large dynamic ranges, small interelement interferences, and a satisfactory precision.
From the investigation of the elemental distribution in marine invertebrates, the highest concentrations of transition elements were found in the kidney of the scallop. It was found that the liver of the lobster contained high levels of copper and cadmium. Especially, the cadmium concentration in the liver was about two thousand times higher than that of the abdominal muscle.
Gel filtration profiles (Sephadex G-75) of iron, copper, zinc and cadmium in livers of marine organisms varied according to species. Moreover, a significant difference in the chromatogram of copper was observed among the oyster samples collected from five sampling sites. The ratio of the third peak area indicating the lowest molecular weight (below 5, 000) to the whole was related to the total amount of copper in the liver of the oyster.
The result by analytical electron microscopy indicated that iron, copper and sulphur were localized in granules of epithelial cells of the oyster gills. In contrast, these elements were not detected in other analytical points such as nuclei or cytoplasm.