Nico V. Berba (February 2010)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
Hydroxyapatite, an inorganic compound which is similar to the structure of the natural bone, is found to be ideal in implantation procedures due to its biocompatibility with the human body. One of the main components of hydroxyapatite is calcium, which can be found in eggshells in the form of calcium carbonate. This study investigated the feasibility of extracting the hydroxyapatite from the eggshells of the estuarine crocodile using the sol-gel method and characterized the synthesized powder through FT-IR analysis. Crocodile eggshells were calcined and reacted with nitric acid, ammonium hydroxide, and potassium dihydrogen phosphate solution. The precipitate from the reaction was acquired and calcined at 700°C. The resulting powders were sent to the Forest Product Research and Development Institute – DOST in Los Baños Laguna for the FT-IR analysis. In the FT-IR patterns of the three samples, strong peaks observed at 3570 cm^-1 of the three replicates, as well as peaks at 635 and 632 cm^-1, verify the presence of hydroxyl group in the synthesized powders. Strong peaks, ranging from 1093 to 962 cm^-1 in the samples confirmed the presence of PO4^3- in the produced powders. The result of this study confirmed the feasibility of producing hydroxyapatite powder using the eggshells of the estuarine crocodile (Crocodylus porosus) by the sol-gel method. This study suggests the crocodile eggshells as a possible material-recycling technology for future waste management and ecology.