FTIR spectroscopic, thermal and XRD characterization of hydroxyapatite from new natural sources

The inorganic constituents of 5 different plants (leaves and stalks) were investigated by using Fourier transformer infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermal analysis including thermal gravimetric analysis (TGA), derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC). These plants are Catha edulis (Khat), basil, mint, green tea and trifolium. The absorption bands of carbonate ions CO32− was exhibited at 1446 cm−1, and the phosphate ions PO43− was assigned at 1105 and 1035 cm−1. At high temperatures (600, 700 and 600 °C) further absorption bands of the phosphate ions PO43− was assigned at the frequencies 572, 617, 962, 1043 and 1110 cm−1 and the vibrational absorption band of the carbonate ions CO32− was assigned at 871, 1416 and 1461 cm−1. X-ray diffraction and thermal analysis confirm the obtained results of FITR. Results showed that the main inorganic constituents of C. edulis and basil leaves are hydroxyapatite whereas the hydroxyapatite content in the other plant samples is less than that in case of C. edulis and basil plant leaves.

When Catha edulis plant leaves are heated at 800 °C, natural crystalline hydroxyapatite was found by XRD patterns.Figure optionsDownload as PowerPoint slideHighlights
► Characterization of main inorganic constituents of Catha edulis as a drug plant in east Africa and Arabian Peninsula.
► The main inorganic constituents of C. edulis plant was found to be the hydroxyapatite.
► The experimental measurements of FTIR, XRD and thermal analysis techniques confirmed the existence of the hydroxyapatite.
► Other different plants were compared with C. edulis plant.