Issue |
J. Chim. Phys.
Volume 75, 1978
|
|
---|---|---|
Page(s) | 761 - 766 | |
DOI | https://doi.org/10.1051/jcp/1978750761 | |
Published online | 29 May 2017 |
Identification précise du constituant minéral des os par étude de son comportement thermique
1
(Laboratoire de Chimie des Solides et des Hautes Pressions, Équipe de Recherche Associée au CNRS n° 263. Université Paul Sabatier, 38, rue des Trente Six Ponts, 31400 Toulouse), France.
2
(Laboratoire de Microradiographie du CNRS, Hôpital La Pitié Salpêtrière, 91, boulevard de l'Hôpital, 75013 Paris), France.
La décomposition thermique de l'os périostique de veau intervient en trois étapes principales. On étudie celle-ci en suivant la variation des teneurs en hydrogène en carbone et en azote d'un échantillon au cours de son évolution thermique. On compare ce comportement thermique à celui de phosphates synthétiques déficients en ions calcium qui contiennent des ions carbonate et des ions [math] et on en déduit la constitution du phosphate biologique naturel.
Abstract
Thermal decomposition of the veal periostal bone is studied by determining the variation of hydrogen carbon and nitrogen amount in a sample heated in the air during two hours at temperatures varying from 20 to 900 C. The curves corresponding to the hydrogen and the nitrogen amount versus carbon amount shows that :
- 1)
the sample looses water between 20 C and 275 C ; the water lost between 20 C and 150 C is associated to both the organic phase and the mineral phase; the water lost between 150 and 275 C is associated to the mineral phase;
- 2)
the organic phase is oxydated between 200 and 400 C; the gross chemical composition remain the same during the phenomenom ;
- 3)
the mineral phase looses water between 400 and 600 C ;
- 4)
the mineral phase looses carbonate ions between 400 aid 800 C.
These results allow to explain the three steps observed in TGA curves of the veal periostal bone sample. The first one corresponds to the loss of water associated to the organic and the mineral phases. The second one corresponds to the decomposition of organic phase on which the elimination of the water associated to the mineral phase is superimposed at the beginning and the end of the phenomenom. The third one corresponds to the decomposition of carbonate ions belonging to the mineral phase.
This thermal évolution is compared to that of the apatie calcium deficient phosphates containing [math].
© Paris : Société de Chimie Physique, 1978