Metallic trace element determination in bio -minerals. Chemical extraction and quantification.

SOLDATI, ANALIA L.; NASCIMIENTO JÄHNKE, SAMARA; VICENTE VILAS, VÍCTOR; BAUMANN, WOLFRAM

Salamanca, España

Conferencia; Euroanalysis XIII; 2004

Sociedad Española de Química Analítica

The presence of metals is studied in the surface shell layer of marine gastropods of the family Cypraeidae. These snails present a transparent, brilliant and smooth coverage on their surface, which give them their common name of "cowry" or "porcelain snails". This about 40 mm surface is not only interesting because of its beautiful aspect, but also since it plays a protective roll against epibiotic agents. Metallic trace elements (Mn, Co, Fe, Zn, Cr, Mg, Cu, etc.) of Cypraea snails have been determined in different shell layers [1, 2]. The present research is towards elucidating the form of binding of selected metals in these layers, with emphasis on the outer periostracum. The results may also hint on the kind of role metals may play in the adhesion properties or the protective adaptation defense. The organic fraction was analyzed by protein concentration and mass distribution. For the elemental analysis different analytic techniques such as Instrumental Neutron Activation Analysis, Inductive Coupled Plasma -Mass Spectrometry and Microprobe, were used and the results compared. In conclusion, the result of this study shows a correlation between the protein content in the different layers and the metal distribution. 1-Y. Dauphin, A. Denis (2000) Structure and composition of the aragonite crossed lamellar layer in six species of Bivalvia and Gastropoda, Comp. Biochem. and Physiol. Part A, A26, 367. 2-J. Marxen, W. Becker (1997) The organic shell matrix of the freshwater snail Biophalaria galabrata. . Biochem. and Physiol. Vol 118B, N°1, 23.