Evaluation of Extracted Cow Bone Hydroxyapatite

Hydroxyapatite (HAp), a calcium phosphate compound, is essential in biomedical and environmental applications due to its biocompatibility and adsorptive properties. The objectives of this study were to evaluate the compositional and structural integrity of hydroxyapatite extracted from cow femur, ribs, and skull bones by calcining the bones and analysing the resulting HAp powders using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-ray fluorescence (XRF), and X-ray Diffraction (XRD) techniques. FTIR analysis verified the presence of distinctive phosphate and hydroxyl functional groups in all samples, indicating successful conversion to HAp. SEM micrographs showed porous, uneven surface morphologies appropriate for biointegration. XRF verified calcium and phosphorus as dominating components. The oxide composition was further confirmed by XRF analysis, which showed that the most prevalent components were calcium oxide (CaO) and phosphorus pentoxide (P₂O₅), but with slightly different relative proportions across bone sources. The rib sample showed a higher magnesium oxide level, whereas the skull bone sample had the greatest CaO concentration. The concentrations of the different elements in the samples were not significantly different (p>0.05). XRD analysis confirmed phase-pure nanocrystalline hydroxyapatite with the main (211) peak at 31.8° and crystallite sizes between 60–70 nm, indicating high crystallinity and structural consistency. These nanoscale features enhance similarity to natural bone and bioactivity. The findings show that bovine-derived HAp maintains key structural and compositional characteristics across anatomical sources, making it a practical and affordable substitute for synthetic hydroxyapatite in biomedical and environmental applications such as contaminant remediation and bone restoration.