Carbonate substitution in the mineral component of bone: Discriminating the structural changes, simultaneously imposed by carbonate in A and B sites of apatite

Abstract

The mineral component of bone and other biological calcifications is primarily a carbonate substituted calcium apatite. Integration of carbonate into two sites, substitution for phosphate (B-type carbonate) and substitution for hydroxide (A-type carbonate), influences the crystal properties which relate to the functional properties of bone. In the present work, a series of AB-type carbonated apatites (AB-CAp) having varying A-type and B-type carbonate weight fractions were prepared and analyzed by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and carbonate analysis. A detailed characterization of A-site and B-site carbonate assignment in the FTIR ν3 region is proposed. The mass fractions of carbonate in A-site and B- site of AB-CAp correlate differently with crystal axis length and crystallite domain size. In this series of samples reduction in crystal domain size correlates only with A-type carbonate which indicates that carbonate in the A-site is more disruptive to the apatite structure than carbonate in the B-site. High temperature methods were required to produce significant A-type carbonation of apatite, indicating a higher energy barrier for the formation of A-type carbonate than for B-type carbonate. This is consistent with the dominance of B-type carbonate substitution in low temperature synthetic and biological apatites.

In situ syntheses of hydroxyapatite‐grafted graphene oxide composites

“…The bending vibration of the CO 3 2− is at 874 cm −1 , as expected from the literature, for carbonate located in the phosphate site of the apatitic structure ( B type ; Madupalli et al, ).…”

“…Madupalli et al () described in detail the positions of the peaks related to the different substitutions, even if their operating conditions were a bit more drastic than ours, using higher reaction temperature and achieving higher levels of A type carbonate in their AB‐type apatite.…”

Application of FTIR spectroscopy for analysis of the quality of honey

“…Typically, the characteristic differences in the FTIR spectral analysis for natural honeys were observed. It was probably related to the content of carboxylic acids in different types of honey resulting from the floral origin, geographic location and possible environmental pollution [2,[12][13][14][15][16][17]. Similarly as for alcohols, the O-H stretching vibration band in carboxylic acids is very broad and occurs in the field of 3300-2500 cm -1 [18][19][20][21][22] with the maximum at 3000 cm -1 .…”

The Assessment of Bone Deterioration with Nuclear Magnetic Resonance Spectroscopy in a Multidisciplinary Context: The Case of the UNESCO World Heritage Site of Sedlec, Czechia

“…The interpretation of the cell parameters (Table S1) is less straightforward, since different ionic substitutions into the apatite structure have opposite effects on the lattice parameters (Madupalli et al . ). In fact, when considered alone, or related to the crystallite size, the cell parameters are usually not very informative (Schmahl et al .…”

“…Since larger apatite domains are considered the results of the intervention of post mortem processes (such as Ostwald ripening and dissolution/reprecipitation) (Cazalbou et al 2004), sample 4 should be the more deteriorated. The interpretation of the cell parameters (Table S1) is less straightforward, since different ionic substitutions into the apatite structure have opposite effects on the lattice parameters (Madupalli et al 2017). In fact, when considered alone, or related to the crystallite size, the cell parameters are usually not very informative (Schmahl et al 2016).…”