Inter-species variation in bone mineral

Abstract

Bone is a complex heterogeneous composite material with organic and inorganic components. The inorganic component; bone mineral, is a poorly crystalline, non-stoichiometric form of calcium hydroxylapatite. A model for the general structure and composition of bone mineral has been established within the literature. However, the nature and extent of variation in bone mineral composition and structure has, to date, been poorly understood. This situation also applies to the general response of bone mineral to heat treatment and variation in this response. This thesis presents the results of an investigation of inter-species variation in bone mineral characteristics of unheated bone and bone heated to temperatures of 600 °C and 1400 °C. Twelve different animal species were investigated, including human bone. X-ray diffraction analysis was the primary analytical technique employed. The Rietveld method of full profile fitting of diffraction data was used to quantitatively investigate characteristics of unheated and heated bone such as the weight percentages of the thermal decomposition products of bone mineral. Infrared spectroscopy, inductively coupled plasma – atomic emission spectrometry, pyrohydrolysis – ion chromatography and combustion – gas chromatography were also employed to obtain further data regarding the chemical composition of bone. Biological ii control of bone mineral composition and structure and the chemical basis for the variation observed within the results were explored. Significant inter-species variation in bone mineral composition and structure and also, the response of bone to heat treatment have been demonstrated by the results of this thesis. In particular, human bone is significantly different from bone of all other species investigated.