XAFS STUDIES OF SOME TRANSITION-ELEMENTS HIGHLY ACCUMULATED IN SEASHELLS

XAFS analysis was used to reveal local atomic environment of manganese in the intracellular and extracellular granules from kidney tissues i n several kinds of marine bivalves. The Mn K-absorption spectra of the kidney granules were measured in a fluorescence mode. The overall spe ctral shapes and the positions of the Mn K-absorption edge of the kidn ey granules of the bivalves are similar to each other and somewhat res emble those of eosphorite (MnAl(PO4)OH)2.H2O) which contains Mn(II). T hese results, combined with those of IR analysis, suggest that mangane se in the kidney granules exist as a phosphate with 6-fold coordinatio n of oxygen atoms.