FT-Raman spectroscopy: A tool for monitoring the demineralization of bones

A nondestructive analytical method based on the use of Fourier transform Raman spectroscopy (FT-RS) for identification and quantitative analysis of hydroxyapatite (HAP) and collagen (COL) In bones was developed. A calibration curve based on the Raman spectra of known powder mixtures of HAP-COL was constructed with the use of the Raman bands at 960 cm(-1) for HAP and 2937 cm(-1) for COL. It was found that I-960/I-2937 = 0,46/W-c - 0.36, where I-960 and I-2937 are the relative intensities for the 960 and 2937 cm(-1) Raman bands, respectively, and W-C represents the weight fraction of collagen. The detection limit for HAP and COL was found to be 2.8 and 0.6 wt %, respectively. The potential of using RS for an in vitro point-by-point analysis ("mapping") of bones was demonstrated successfully on an artificially demineralized ox femur sample.