Associated water and organic compounds in coral skeletons: Quantitative thermogravimetry coupled to infrared absorption spectrometry

Samples from coral skeletons belonging to six species have been submitted to thermogravimetric analysis in the temperature range between 20° and 550°C. Weight losses are interpreted on the basis of simultaneously recorded infrared absorption spectra at specific wavelengths for water and CO2. The organic + water content of coral skeletons represents up to 2.5% of the total weight. Additionally, it is shown that during heating the main part of water remains linked to organic compounds up to 275°–330°C, suggesting organic materials associated with the skeleton are hydrated.