EFFECT OF HOLDING TIME ON EXTRACTION OF NATURAL HYDROXYAPATITE FROM GOAT BONE WASTE FOR BIOMEDICAL APPLICATIONS

Abstract

Hydroxyapatite (HAP) is a very essential biomaterial used in orthopedics and dentistry to support bone healing processes as it shares chemical similarities with natural human and animal bones. Extraction of hydroxyapatite has been done both synthetically and naturally from animal bones. However, extraction of HAP from natural sources is challenged by the appropriate choice of processing parameters such as holding time and temperature that will enable the production of hydroxyapatite that meets the standard. This work investigated the influence of varying holding time on the physico-chemical properties of HAP obtained from goat bone (GB) waste by heat treatment. GB femur was obtained; washed; dried; pulverized and sieved to obtain GB powder of ≤ 500 µm that was calcined at 900°C and 1000°C and soaked for 1hr., 2 hrs. and 3 hrs. The composition, structure and morphology of the uncalcined and calcined powders were studied using Fourier Transform Infra-Red Spectroscopy (FTIR), X-ray diffractometry (XRD) and scanning electron microscopy (SEM), respectively. The FITR result confirmed presence of associated functional groups consisting of phosphate ions (PO43−), hydroxyl ions (OH−) and carbonate (CO32- ) ions in the synthesized HAP, but the phosphate ions (PO43−) were most prominent. XRD analysis revealed similar crystallographic peaks of pure HAP. Increase in holding time led to decrease in crystallinity. SEM analysis revealed changes in the morphology of the samples with increase in holding time and temperature due to decomposition of organic compounds in calcined GB. The surface morphologies became finer with increase in holding time. Thus, holding time is an important parameter in extraction of HAP from goat bone waste.