Naslov
Shell layers of Ostrea edulis as an environmental indicator of TBT pollution: the contribution of surface techniques

Autori
Medaković, Davorin ; Traverso, Pierluigi ; Bottino, Carlo ; Popović, Stanko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
European Conference on Applications of Surface and Interface Analysis / Werner, Wolfgang S.M. - Beč : Vienna University of Technology, 2005, 159-159

Skup
11 th European Conference on Applications of Surface and Interface Analysis

Mjesto i datum
Beč, Austrija, 25.09.2005. - 30.09.2005

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
XRD; XPS; SEM; Tin; Silica; Chamber; Oyster

Sažetak
Biomineralization is a complex combination of biochemical and physiological processes, depending on the endogenous activity of the organism and exogenous environmental influence. Although mollusc shells are considered to be a powerful tool for monitoring environmental conditions, alterations in biomineralization processes influenced by environmental changes have been insufficiently investigated so far. X-Ray powder Diffraction (XRD) was used to study the mineral composition of the shells of the European flat oyster Ostrea edulis (Linnaeus), collected from two localities in the East Adriatic Sea (Croatia). The variability of shell element chemistry between two different shell layers were determined by X-Ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM). XRD showed that the dominant component of outer prismatic foliated shell layer is calcite with traces of aragonite and halite. The chambers of the inner nacreous shell layers are built mainly of magnesium calcite. Chemical element analysis given by XPS and SEM confirmed that beside carbonates other minor elements could be incorporated in the oyster shells. The silicon (Si) is ranging from 0, 1 to almost 1, 5 atomic % (A %) in the outer shell layers whereas its amount becomes lower and difficult to quantify in the inner shell layers. On the contrary, tin (Sn) is clearly detected only in the chambers of the newly formed inner nacreous layer, in a concentration that can be estimated, according with both XPS and SEM analysis, in the order of 0.1-0.2 A %. Tin in the oyster shells is environmentaly induced. A possible formation mechanism and specific ecological factor that could influence the precipitation of tin in the different shell layers of O. edulis is discussed.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Geologija, Biologija

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