Texture Characterization of Otolith from Chrysochir Aureus by X-Ray Diffraction, Infrared Spectroscopy and Thermogravimetric Analysis

Abstract

Crystal texture of otolith from chrysochir aureus was characterized by digital cammera,x-ray diffraction, infrared spectroscopy and thermogravimetric analysis. The results showed that there were several rounded aragonite crystal, with 1/2 long sulcus in otoliths. The samples were mainly composed of CaCO3 (98.38%) with worse stablity aragonite structure, and second phase materials, by XRD; The strongest absorption peak 1477cm-1 of IR spectra related to carbonate structure, peak 1083 cm-1 and 855 cm-1 belonged to CaCO3 aragonite; and the TGA curve could be separated into three stages: evaporation of water, release and combustion of volatile inorganic salts and organic compounds (1.62%), then decomposition of CaCO3 (98.38%). The crystal texture characterization could rich the basical study of chemistry for Chrysochir aureus, and could be applied to build a chemical biology database for classification of fish otoliths.